Irregular gestational sac

Hi,

I had spotting since week 4 . Now I am week 6 and 4 days. Spotting is there till now. Sometimes fresh blood sometimes brown particles as i pee. My HCG did not double but raised 60% initially. I checked for heartbeat at 6 weeks 1 day. I found nothing. So we decided I miscarried. 6 week 4 days I went to doctor to do the procedure and I found a heartbeat with 128 bpm. I was shocked. Now I have a irregular gestational sac. It's not round. They say I am going to miscarry. I am very scared. Pls help. Did any of you go thru the same. Pls pls pls help. Very scared :(