lump on forearm

I’m 18, female, asian

Hi guys, I noticed this lump on my left forearm saturday (i’m not sure how long it’s been there). At first it was painless and when I press down it doesn’t hurt but feels like a pressure. Now it does hurt when i press down but honestly it might’ve been due to having it massaged. It honestly just feels like my skin but with a lump. it’s squishy but i don’t really notice it being moveable(?)I know it’s not just a “regular arm bump” because I don’t have it on my right arm in the same place. I’ll try to attach a pic or two in the comments