Can You Have Your Period During Pregnancy?

Every once in a while, a story pops up about a woman who didn’t realise she was pregnant until she was in labour.

For most women, this sounds completely impossible!

Wouldn’t you notice the lack of menstrual cycles? Perhaps nausea, or at least a growing belly, would grab your attention.

When questioned about why they hadn’t realised they were expecting, some will say, “I was still having what I thought was my period, so I didn’t think I could be pregnant.”

Huh?!

We know some women have bleeding during pregnancy, but how could they confuse it with a period?

Can you have a period while you’re pregnant?

What Is Your Period?

In order to know whether or not you can have a period during pregnancy, you need to understand exactly what your period is.

The menstrual cycle is divided into four parts:

• Your period – when you’re bleeding
• The follicular phase – when an egg begins to mature for ovulation
• Ovulation – when your body releases a mature egg
• Luteal phase – the time after you ovulate, which lasts until a fertilised egg implants, or an unfertilised egg dies and triggers your period

A period isn’t simply bleeding. A period occurs when your progesterone drops, because no fertilised egg has implanted.

A drop in estrogen triggers your body to shed the uterine lining, which causes you to have a period.

While your period seems like only bleeding, it contains blood, mucous and endometrial (uterine lining) cells.

If you’re pregnant, you cannot have a true period.

Having a true period is the result of a full menstrual cycle, and the shedding of your uterine lining, which wouldn’t be possible during a pregnancy.

To learn more about your period and menstrual cycle check out BellyBelly’s article Menstrual Cycle – Stages, Phases and What To Expect.

How Could Bleeding Mimic A Period?

Some bleeding during pregnancy is actually quite common, especially during the first trimester. The menstrual cycle also varies among women. Some women have lighter periods, and therefore a bit of spotting could be confused with a regular cycle.

One study found that 25% of participants reported bleeding during their first trimester, and 8% reported heavy bleeding, similar to a period flow.

What Causes Bleeding During Pregnancy?

There are several things that can cause bleeding during pregnancy:

• Implantation bleeding – A fertilized egg implants around the time many women are expecting a period. As it buries into the uterine lining, some women experience a bit of spotting or bleeding as a result. It’s possible to mistake this bleeding for a light cycle. A woman might not consider pregnancy until she misses another cycle.
• Breakthrough bleeding – During the early part of pregnancy your body is producing progesterone and other hormones which prevent your body from triggering the start of your period. Occasionally, hormone levels are not quite high enough to prevent some breakthrough, menstrual-like spotting or bleeding. This bleeding can be quite confusing, as it often appears around 4, 8 or 12 weeks of pregnancy, which is when many women would expect their periods. Once the placenta takes over hormone production, is not common to have breakthrough bleeding.
• Placental bleeding – Placenta previa is when the placenta is near, or partially or fully covering the cervix. Placental abruption means the placenta partially or completely separates from the uterine wall. Placental lakes are enlarged spaces in the placenta, filled with maternal blood. These, and some other placental complications, can often cause  painless vaginal bleeding, later in the second or third trimesters.

As well as these, there are other possible causes of bleeding during pregnancy.

Read more about other causes of bleeding during pregnancy in BellyBelly’s popular article, Bleeding During Pregnancy – 7 Causes Of Bleeding.

What Should I Do If I Suspect Pregnancy And I’m Bleeding?

If you suspect, or know, you are pregnant, and you experience any bleeding or spotting, you should contact your healthcare provider. Bleeding during pregnancy can occur in healthy pregnancies that will continue to term. However, bleeding during pregnancy is sometimes indicative of complications, including pregnancy loss.

If you’re having what appears to be a regular period, it is unlikely that you’re pregnant. However, any time you think you could be pregnant, it’s good to be in contact with your care provider.

If you’re unsure about whether or not you might be pregnant, check out BellyBelly’s article, Am I Pregnant?