Petechiae?

Hi other big boob havers. Im in my early 40s , recently (last 6 months to year) Ive been noticing petechiae on my breasts after lifting or carrying things. Theyre nowhere else on my body & are only at the TOP of my breasts & the dots are scattered probably 8 to 12 at a time total , only there no where else on my body. I wear only sports bras , with underwire. Normal breast sonogram & mammogram less then a year ago. Haven't had bloodwork done in a bit but last time was normal. Does this happen to anyone else?