Im12wks pregnant & started bleeding yesterday. my baby looked okay in the ultrasound and ob said my cervix looked irritated, but still high&closed, & i still have a small sch. is it possible i could still miscarry after seeing a heartbeat yesterday?

It's possible: Any pregnant woman may miscarry as a normal part of life. A significant number of pregnancies naturally miscarry. If a woman has recurrent miscarriages, there are some known causes (other than bad luck) such as genetic disorders (may be chromosomal abnormality), autoimmune causes (like anti-phospholipid syndrome), anatomic causes (may be a malformed uterus), or environmental causes (like smoking).