Armpit lump

Hi, so about a month ago I found a lump under my right armpit. A very small lump, brown in colour, hurts a little when I touch it and there is a white hole (not hole, but something white in circle) in the middle. When I squeeze it, some clear fluids come out. My right armpit is also a little fatter than the other one. I did a self-check on my breast, and found no lumps in both breast. I went to 2 doctors, and they say its nothing to worry about. So, the question is should I worry? or should I go to the doctor once again? Thank you