I'm pretty sure I am 8 weeks pregnant, based on my LMP of 11/25/15. I went for a Transvaginal US…

I'm pretty sure I am 8 weeks pregnant, based on my LMP of 11/25/15. I went for a Transvaginal US yesterday due to minor brownish spotting and mild groin pain on right side. My OB/GYN took a look and said there was Zero active bleeding and my cervix was closed and had good depth.

He ordered a stat US and confirmed pregnancy at a little over six weeks, and the babies HB was irregular and intermittent. (Meaning they were able to see it one second, then gone the next.) We were so upset. I've had two normal pregnancies in the past and a twin pregnancy that was made happen by IVF with ICSI. Both fertilized eggs implanted and I delivered via ECS @ 24 weeks. Both twins alive and now 3 years old.

So what I believe is happening is that I AM actually 8 weeks, but the baby stopped really growing about two weeks ago and we have a HB that will soon stop. We have an appointment tomorrow to have another US done to see if the HB picked up.

What are your thoughts??!! I am 36 years old. Had 2 term pregnancies, 2 terminations (please don't judge) one before my twins and one after. And now 2 years after my husband had his vericocelectomy, we conceived this time.

Should I expect the HB to increase or there not be one at all?