There's always a chance of miscarriage whether you've had one or none before, healthy or not healthy.....1 in 4 pregnancies end in miscarriage which is a frightening statistic.....Like Praying4MiniMe said, if you;re not having bleeding or cramping, I wouldn't worry too much....Lots of luck with your pregnancy!
Most the time you can't see anything until like the 8th week, so it could still be too soon. If your not cramping severly or bleeding, i wouldn't worry too much. Keep your head up. Good luck!
Sorry for your lost, there is a chance of having another one. You dont want to think like that, just be positive and it should all work out. I believe you will go all the way this time. Keep the faith.