This happened to a friend of mine Fellow Traveller. She was very concerned as she had also had a couple of miscarriages and was 39 at the time. I'm glad to say that all turned out fine and she is due in early March. So try not to worry too much. I think she went and got her hcg levels tested so it may be worth asking about that if it will put your mind at ease. I think it just involves a blood test that can be done by your GP rather than waiting for an ultrasound to be done by a specialist.