Young women often complain of “pimples” (also called acne) just before their periods. The medical term for this is called “premenstrual acne” and it’s usually due to the hormones that are active before your period. Some girls are more sensitive to these hormones than others. So, even if you’re careful about taking good care of your skin, chances are you may have a mild to moderate breakout before your period. The good news is that once your period is over the acne usually goes away.