Pregnancy bleeding help!

Okay so I'm almost 8 weeks and I e been spotting almost everyday the past few weeks I have had 3 ultra sounds bc of the bleeding cervix is closed, levels are fine and we saw the baby at 7 weeks one day with a heartbeat of 164. They can't figure out why I'm bleeding am I at risk for miscarriage ? I'm really scared and it took us a long time to get pregnant. They thought I might have endromesious but I was scheduled for a procedure the month I got pregnant so I never had the test.