We should remember that everything starts in the endometrium1. It begins to form even before ovulation, and may not reach the ideal thickness. This results in a lighter menstruation than usual due to the small amount of accumulated blood. This low bleeding or light menstruation with a different appearance, which appears on the days when a woman would expect her normal blood flow, can raise suspicions of pregnancy.
The body begins to secrete more progesterone as soon as menstruation ends. At this stage, the endometrium already starts to thicken and accumulate blood at the bottom of the uterus, preparing for a possible pregnancy. The endometrial blood changes a lot according to the hormonal cycle as it approaches the ovulation phase. The so-called GnRH promotes and regulates the production of other hormones during the ovulatory phase, such as FSH, which stimulates estrogen to rise and makes the follicles grow2.
The problem arises when this cycle of essential fertility hormones does not occur correctly. This hormonal pause can happen to any woman and is called an anovulatory cycle. A cycle without ovulation produces a low volume of endometrial blood, and as a consequence, it will produce a shorter and different menstruation.
Women with heavy cycles largely have a stronger estrogenic stimulus than women with lighter flows. This is because they produce more hormones during the fertile window and after. Women with heavy menstrual cycles theoretically would have greater chances of becoming pregnant quickly than other women with lighter menstrual flows. Why is that? Because this can be a possible sign that the body is producing an endometrium suitable for embryo implantation. A very thin endometrium may not be sufficient for the embryo to implant. However, if a woman with a heavy flow experiences a light flow or light menstruation, this can be a sign. It might not be a light period, but actually signs of so-called implantation bleeding
Can Light Bleeding During the Menstrual Period Mean Pregnancy?
Yes. However, we should remember that the most likely hypothesis should prevail. One hypothesis is that the cycle was anovulatory. Therefore, caution when considering pregnancy should be above any expectations, no matter how many positive indications for pregnancy there might be. Light menstruation can be confused with implantation bleeding3. It is not uncommon for a woman to get excited upon seeing a small amount of spotting, or a much lighter flow than she is used to. However, we must remember that differences can occur in every cycle. Therefore, what a hopeful woman trying to conceive may believe is a sign of implantation might simply have been a cycle with unbalanced hormones.
Pregnancy only truly consolidates after implantation, but in the vast majority of cases it is not visible, that is, with apparent bleeding. Statistically, cases with bleeding are rare compared to the rest, in which pregnancy can only be confirmed after a missed period. Just as non-apparent implantation bleeding is the majority, a light menstrual flow in the overwhelming majority of times means this woman is menstruating, so it is not a sign of pregnancy.
We can say that these cases are the exception, not the rule. That’s why it is important to wait, even with a lighter flow. As mentioned before, light menstruation is the shedding of a less voluminous endometrium, due to a hormonal imbalance. Bleeding that fills (or nearly fills) pads should be considered as menstruation.Likewise, light but dark menstruation is also due to changes in the endometrium because of hormonal reasons.
Important: Do not be alarmed if you have light menstruation. Wait a few days or hours and observe. Usually, the flow will increase. If it doesn’t come for several days and you only notice small stains or pink blood without any flow, you can take a test to check for pregnancy.
Women who take hormonal medications (contraceptives, morning-after pills), may have lighter bleeding due to the medication itself. Pregnant women do not menstruate. If the pregnancy is confirmed and the woman has bleeding, be careful. There is a risk of losing the baby, so talk to a doctor as soon as possible.
Important Tip: A reliable test is extremely important, so we recommend the one with the best sensitivity, 10mUI. The Famivita pregnancy test can detect pregnancy even before a missed period. You can find the test here.
Also read: Is It Possible to Get Pregnant Without Menstruating?
