How Your Period Affects Your Chances of Getting Pregnant

A period can be a nuisance, but it can feel even more frustrating when you're trying to conceive and your period comes early. If you've ruled out the possibility of that early period being implantation bleeding, you might be left disappointed and wondering what's going on. Well, one way to look at it is that your period can be your body's way of communicating with you.

That's right: What many people don't realize is that your period can be a window into your health and fertility. It helps you track your cycles, know (approximately) when you're most fertile, and discover clues about your chances of getting pregnant.

If you have regular periods and aren't getting pregnant, factors like cycle length and how heavy your flow is can all impact your ability to conceive. That's because your periods are affected by the hormones that regulate your cycle, help you get pregnant, and maintain a healthy pregnancy. So, when hormone levels become off-balance, sometimes due to underlying medical conditions, stress, or extreme changes in diet, there's a good chance your menstrual cycle will get thrown off, too.

Read on for some common concerns people face with their period and what they can mean for your fertility. This information can help you know when to consult a doctor about how your period could affect your chances of conceiving.

Missed Period

If you're not getting pregnant, and your period isn't showing up as expected, it's a good idea to talk to a health care provider to get to the bottom of the issue. That's because an irregular cycle has a two-pronged effect on your fertility.

First, it'll be much harder to pinpoint those key days leading up to (and including) ovulation when getting pregnant is most likely; an ovulation calculator won't work as well in these cases. Second, and more importantly, repeatedly missing periods often indicates underlying issues that can affect your fertility. Some are more complex, while others are relatively simple to solve.

If you're wondering what can cause a missed period outside of pregnancy, there are several possible causes. These include:

• Breastfeeding
• Menopause
• Some forms of birth control
• Medications, including some antidepressants and blood pressure medication
• Scar tissue from previous procedures (for example, D&C, cesarean, or fibroid treatment)
• Low body weight
• Inadequate caloric intake
• Stress
• Burning more calories than you take in
• Polycystic ovary syndrome (PCOS)
• Thyroid problems
• Pituitary tumors

"PCOS is probably the best-known cause of irregular cycles. Hypothyroidism can sometimes cause amenorrhea too, as can high prolactin levels, zinc deficiency, extreme dieting or weight loss, or very intense exercise," says Lauren DeVille, NMD, a naturopathic doctor at Nature Cure Family Health in Tucson, Arizona.

Many of these concerns can easily be fixed or reversed with the help of an OB-GYN, who can also refer you to a fertility specialist if necessary.

Abnormal Flow

If you're getting your period every month, you're ahead of the game when it comes to your chances of getting pregnant. But your flow can also offer insight into your fertility as abnormally heavy or light periods can sometimes point to issues that need to be solved before conception.

So, if you're having regular periods but not getting pregnant, your flow could hint at the cause.

Heavy periods

According to the Centers for Disease Control and Prevention (CDC), the following are indicators of a heavy period:

• Needing to change your menstrual product after less than two hours
• Passing clots the size of a US quarter or larger
• Bleeding longer than seven days

According to Jessica Shepherd, MD, an OB-GYN at the University of Illinois at Chicago, an extremely heavy menstrual flow is called menorrhagia. In addition to the above signs, people with heavy periods might also experience dizziness, fainting, anemia, or shortness of breath during their period. In severe cases, a person might require a blood transfusion due to blood loss.

An unusually heavy period could affect your fertility, even if you have regular periods. Many possible underlying causes of very heavy periods could lead to an inability to get pregnant or sustain a healthy pregnancy. According to ACOG, causes of very heavy periods include:

• Uterine fibroids or polyps
• Endometriosis
• Adenomyosis (when uterine tissue grows into the muscular uterine wall)
• Irregular ovulation
• PCOS
• Hypothyroidism
• Bleeding disorders
• Some medications, especially blood thinners and aspirin
• Copper IUD
• Endometrial cancer
• Pelvic inflammatory disease
• Ectopic pregnancy or miscarriage
  

Light periods

When you're having difficulty conceiving, having a light period can sometimes indicate a potential fertility problem. Light periods could be caused by being underweight, stress, or approaching perimenopause.

One of the underlying medical issues associated with light periods that medical providers will look for is PCOS, a condition where people produce higher-than-average androgen hormones. PCOS is one of the leading causes of infertility. But the good news is that proper medical treatment to help keep hormones on track makes it possible for many people with PCOS to have a healthy pregnancy and carry a baby to term.

In most cases, however, having a light period isn't anything to be too concerned about. If you've always had a pretty light period, or if it's always been on the short side, this is unlikely to affect your chances of getting pregnant. But if your light flow is a sudden change that can't be explained by increased stress or dramatic weight loss, you may want to look into what's causing such a minimal period.

Cycle Length

Both abnormally long and short menstrual cycles can impact your fertility. Drastic differences in cycle length can signal hormonal imbalance or other underlying medical issues.

The average cycle length is 28 days. But of course, we're all different, so there will always be some variation in cycle length. In fact, a 2020 study of 1.5 million menstruating people found that only 16% of participants had a 28-day cycle.

Cycle length matters because it can indicate whether ovulation occurs regularly. It also is a clue as to when you ovulate.

Long cycles

A long time between periods can mean you aren't ovulating regularly. Long cycles often indicate an anovulatory cycle, or a cycle where your body doesn't release an egg at all. As you can imagine, not ovulating can make the baby-making process more challenging.

Even a 30-day cycle can feel like an eternity when you're trying to get pregnant. However, longer-than-average cycles aren't usually an issue if your cycle is just a few days longer than average. According to the Office on Women's Health, a cycle that lasts up to 38 days is still within the range of "regular."

Also, rest assured that occasionally having cycles that are longer than usual is pretty normal. Minor things like travel, stress, or even illness can delay your period by a few days. But if you're going on 45 days or more, or if longer-than-average cycles are becoming the norm for you, it's time to figure out what's happening.

Many of the things that cause missed periods and other anomalies are the same things that cause long cycles. Hormone imbalance in the thyroid and adrenal glands, uterine polyps or fibroids, PCOS, or obesity can all play a role.

Short cycles

On the flip side, if you've noticed that your period comes early or you're getting your period more than once each month, there's a good chance your cycle length may be abnormally short. If you think this equates to even more chances to try to conceive, sadly, that's not always the case. An abnormally short cycle can indicate, among other complications, a luteal phase defect.

"The luteal phase is the second half of the cycle, after ovulation. During this phase, progesterone rises to nourish the endometrium in case of implantation. It takes about seven days after ovulation for implantation to occur, so a luteal phase shorter than this makes pregnancy unlikely. Ideally, you need the luteal phase to last around 14 days," says Dr. DeVille.

According to the American Society for Reproductive Medicine, a typical luteal phase lasts 12 to 14 days but can range from 11 to 17 days. Clinically detected luteal phase deficiency is defined as a luteal phase lasting less than 10 days.

Other signs of a luteal phase defect include spotting and repeated early miscarriages. The solution often lies in fertility drugs like Clomid (clomiphene) or progesterone suppositories. So, if you are diagnosed with a luteal phase defect, know that it's typically a treatable problem, and you'll likely have little trouble conceiving once it's corrected.

Interestingly, research also shows that while short-term fertility may be lessoned for those with a shorter luteal phase, conception rates after 12 months of trying are often similar to those with longer menstrual cycles.

Spotting

Spotting between periods can happen from time to time. But if you're experiencing regular spotting before your period starts every month or having lots of breakthrough bleeding between cycles, your hormone levels may be slightly off balance. Spotting is more common during the first few years after your period starts and as you approach menopause.

"Spotting usually occurs when progesterone levels are too low to keep the endometrium in place. Or alternatively, if estrogen levels are too high," explains Dr. DeVille.

If you're having lots of mid-cycle bleeding, you might consider trying an at-home hormone test and taking the results to a health care provider. They can review your test results and determine what type of treatment you might need to increase your chances of getting pregnant.