Easy bruising and petechiae

I've been having this problem for a while, I often find tiny red spots on my skin, especially on my bra line.Also I bruise much easier, ex: I was bitten by a mosquito and after I scratched it for a while I developed tiny red spots and small bruises in that place.I don't have any obvious problems.My thrombocytes are fine, hemoglobin is fine, liver as well and my blood clotting doesn't seem affected, at least if I consider the blood clotting tests I've made.Is there anything else I should check or maybe I can let this go?20,F.