Should I be concerned if this is breast cancer?

17, afab, 4'11, no diagnosis

Hi, I got some really bad hives spreading down from my chest up to my neck, and about an inch past my left ear and almost to the back of my neck on my right ear. It only really came in about 4 days ago when my period started but just progreessed a bit since then. My mom wanted to take me to the hospital(i do not like doctors or nurses at all, no offense but sometimes you guys horrify me)but I blew it off guessing it'd go away a bit after my period. I can be a big dumb dumb sometimes and just now realized okay this might actually be cancerous. I'll add a picture of the rash link down in the comments (idk if that's allowed sorry) And nobody in my family (biologically at least) has any history with cancer if that means anything? thank you in advance