i didnt have sore armpits, i had a swollen lymphnode on the back of my neck, and one right below my trap muscle on my right side, behind the clavical bone.
the one behind my clavical was pretty tender and would randomly feel like this tiny sharp pain, but if i touched it it would feel really tender and just irritated.
i was on medicine to get rid of what was thought to be the cause of it (sinus infection) and the small soreness i was having gradually went away after a few days.
the one on my neck was around for a lot longer, few months, gradually going down. it is pretty much gone now but if i feel around for it around my neck i can still feel it. sometimes they don't go down 100% ever.
EDIT:
i also am allergic to everything and have seasonal allergies, and in the winter times, i'm pretty much a walking cold.