Armpit Lump

[Liralei]

Hi. I'm 14 years old... and this lump under my right armpit is bothering me. It's painful that's why I searched some home remedies. I tried hot compress. It worked... after 1 week, the pain is gone but I'm curious why my lump doesn't go away. Right now, the lump is smaller and I can barely feel it. but when I take a bath, I can feel that there's still a lump.  It's been 2 weeks since it first appeared but it still doesn't go away. in the 3rd week, a lump suddenly appeared again... same with the first one. it feels painful. but after a day, it doesn't feel painful at all and it's too small. I feel like it's completely gone because I can't feel it also. I told my mother about my lump. she said that it could be an infected lymph node... or maybe because of my period. Please help me guys... I'm so worried right now.