I think this sort of worry is something every first time mum goes through, particularly if you have been ttc for a while or experienced a loss previously. I found massage was a way to help me relax. I also made up a little mantra for myself that I said when ever I got worried. It went something like 'This baby will be born strong and healthy and will live a long and happy life', I even found myself saying it a few times in labour when I thought things were not going right. Just think though 4 more weeks and much of the risk associated with the first trimester will be gone. Your doing great honey, hang in there.