Question

So this might be too much information but I need some help, so right before Katie and I went to England my right armpit started to hurt, and there was a significant red bump/area that hurt.  It went away in a few days, but now my left armpit hurts...the same way just not as bad.  What does this mean?  I knew that there are lymph nodes in your pits so maybe from that but I'm not feeling sick or anything...anyone know what this could be because of.  Jen another girl here said her armpit was hurting too!  Ha sorry if this is too much information for you all!