Brown spotting 11weeks pregnant?

I don't know if it's the beginning of a m/c or not. I have already had two before this pregnancy, but they happened before 8weeks. This pregnancy my baby had a heartbeat of 167 at 8weeks and yesterday I went back to the dr bc of the brown spotting and they heard the babies heartbeat with the Doppler and said everythig sounded fine and my cervix was closed. I'm just so scared bc I'm still spotting and with my last m/c (blighted ovum) my cervix was closed with brown spotting. But neither of my other ones had a heartbeat. Any words of wisdom please? I haven't had any intercourse or anything since I found out I'm preg bc I'm high risk