Could The Soreness In Axillary Glands Be A Pre Menstrual Symptom?

Hi. For the past 5 years now, I have been getting sore axillary glands on both sides, and with my personal physician, found out that it coincides with my mentrual cycle. She said, sometimes women get sore breasts, and some get sore armpits too. It usually starts a week before my period and subsides once I get my period. What is happening with my hormones at that point, that makes them hurt?