I went through a similar situation, I lost a baby at 20 weeks, not full term, but they called it a stillborn. I got pregnant right after I stopped bleeding from the stillborn. The did ultrasounds on me too and did not see a heartbeat. i waited untill 10 weeks, and there was still no heartbeat. i was diagnosed with a blighted ovum and given a dnc. Blighted ovums are very common, it means the egg was fertilized but never developed. I waited three months and am pregnant again now, everything looking good so far. i hope the best for your situation. I would say wait to make sure there is no heartbeat, sometimes it is hard to see untill later on, especially if you have a tilted uterus. If it turns out to be a blighted ovum, don't worry. I have gone through sevral miscariages, and when the time is right it will happen! Sending good thoughts your way!