Random breast growth?

Hey there. I’m 19, and my entire life I’ve always had very small, almost non existent boobs. Between an 36 A, to a 32 B. And I’ve only ever worn pushups so my boobs were probably even smaller than that lol. Anyways, within recent weeks (since my last period which was around the 4th-9th) my boobs have DOUBLED in size. I’m at least a C at the moment. They’re so sore to the point where it hurts to even lay on my side or sprint. I have problems with weight fluctuations (I never break 95lbs) so I’ve noticed very small size increases/decreases in my chest before but it’s never anything this drastic. I’m not on birth control, I’m not pregnant, I just had my period but breast tenderness never ligers this long for me. Any thoughts?