over the past few months i have noticed that i get a swelling the size of a golf ball under my left armpit prior to my period which is sore. It seems like the soreness dissipates once my period starts but I cannot tell for sure if the swelling completely goes away. Relative to my armpit on the right side, it seems like there is a mass or growth on the left. I have a doc appt. scheduled for this week but I thought I would check to see if anyone has experienced this. Cancer runs in my family so I am a bit worried.
Any advice or relevant comments would be appreciated.