I am 15w and 3d pregnant. i found out around 7 weeks i had a small subchorionic hemorrhage on the backside of my uterus.will baby aspirin help?

NO. Aspirin: And nsaids (ibuprofen) and fish oil are all blood thinners and could make the bleeding worse. Follow up with ur oby. Take care!

Aspirin doesn't help: A subchorionic hemorrhage/hematoma is a bleed between the pregnancy and the uterine wall. It is an US finding, that if coupled with vaginal bleeding, can potentially increase the risk of miscarriage/preterm delivery, but w/out vaginal bleeding, it's hard to say. Size matters; worse if bigger (covering ~50% of placental bed) or occurring later. It can heal itself, but you just have to wait/watch.