The best time of the cycle for a breast self-exam

October is Breast Cancer Awareness Month. Everyone talks about how important it is to do a regular breast self-exam to have a timely diagnosis, but do you know the best time in the cycle to explore your boobs?

Like many other things in your body, your breasts change during your menstrual cycle—this is thanks to the estrogen-progesterone super duo.

Your reproductive hormones make your breasts more sensitive, thicker, and lumpier at certain times in the cycle. For this reason, it not only matters how you do a self-exam but in what phase of your cycle you do it.

At the beginning of the pre-ovulatory phase, your ovaries produce estrogen, but progesterone levels are low. Progesterone is responsible for some of the changes in your boobs (more on this below). Since this hormone is absent in the pre-ovulatory phase, not much happens to the breasts and nipples at this point in the cycle, making it the best time to perform a self-exam.

Estrogen continues to increase, causing breast ducts to grow. In this phase, your body prepares for a possible pregnancy; the number of progesterone receptors in your breasts increases and the alveoli (the small sacs that drain milk to the nipple) multiply. All this makes your breasts look bigger and firmer these days. 

This is not a good time for self-examination, as the increase in size can hide certain lumps that could be a warning sign.

Right after ovulation, your ovaries produce progesterone, which can cause tenderness, swelling, and inflammation in your boobs.

Before your period, it’s common to notice changes in texture and feel small lumps. According to Dr. Jerilynn C. Prior, founder of the Center for Menstrual Cycle and Ovulation Research (CeMCOR), finding a lump during this phase isn’t necessarily dangerous. Most of the time, an imbalance of estrogen dominance without enough progesterone produces cysts (round balls filled with fluid) or clumps of growing tissue that feel sore when you touch them.

Once your period arrives, your hormone levels drop, and your boobs slowly return to their normal size. However, it’s not a good time for a self-exam since your breasts and nipples can still be tender during these days.

In a nutshell, the best time to check your boobs is one week after your period starts, when your breasts are least likely to be swollen or tender.

It’s not just about how your boobs feel but also about how they look. 

The symptoms and signs to look for are nipple discharge, lumps, and thickening; changes in size, shape, or skin texture (wrinkles or dimples); rash, crusts, or changes in the direction of the nipples; swelling in the armpit or around the collarbone; redness or warmth; and growing veins.

Remember to write down your observations, including the date of your last period and when you performed the self-exam. If you observe any of the signs above, talk to your medical practitioner as soon as possible.

It’s quite important that you do a monthly self-examination, even if you don’t have a cycle due to health reasons, hormonal contraception, or menopause. If this is your case, choose the same day each month for your boobs check-in.

Please remember that a self-exam is not a measure to prevent breast cancer, nor the only thing needed to diagnose it. However, it can make a massive difference between having an early detection or not.

Touching and observing your boobs month after month will help you get familiar with what’s normal and alert you when persistent changes don’t come and go with your menstrual cycle.

Know your body and take care of it!