no heartbeat at 6 weeks

[worriedat42]

I am 6-7 weeks pregnant. Last week, I went in for an u/s due to some ligament pain. They saw an yolk sac but no heartbeat using vaginal u/s. I have no bleeding or heavy cramping. However, I don't have sore breasts, heavy nausea or feeling too tired either. My first hcg level was low ( 636 @ initial ) but jumped to 1800 after the next day. This is my 3rd pregnancy and my first two are healthy ( thank GOD). I am now 42 and is so worried. My Dr. just advised to come back at 9 weeks for another u/s. She thinks it might just be too early. I don't have "typical" pregnancy signs, but no bleeding or cramping so I am praying everything is ok and I am just lucky to not have those symptoms yet. Any advice or thoughts?? Thanks