Hi J.,
I went through the same thing with my second pregnancy - bleeding started at 8 weeks, baby had a strong heartbeat, I had lots of bleeding, docs telling me everything was fine. I ended up miscarrying at 11 weeks. It was devasting but I know that there most likely was something wrong with the baby since each ultrasound was showing less growth then it should have - also I only wanted to have super healthy foods, like I was craving mass quantities of spinach and other veg. After I got the okay from doctors to try again, we got pregnant again within the month and at about 11 weeks with that pregnancy I woke up from a nap to find blood pouring out of my body. I thought for sure I had lost the baby but it was a subchorionic (sp) hemmorage - which I think someone has already mentioned. I was put on bed rest and it resolved itself over 2 months of bleeding like I had a period. I went in for doctor's visits weekly while it resolved. Now I have a beautiful 4 month old boy.
My thoughts are with you and I pray that like many of the women who posted before me, things will turn out well for you. Big hugs because I know exactly what you are going through.