Missed miscarriage

I post a lot. I'm very scared all the time that something will happen to this baby. I'm nine weeks today with lessening symptoms, it seem. I worked out pretty hard yesterday, and didn't have any cramping or bleeding, but I'm afraid I hurt the baby and will find at my 12 week ultrasound that I had a missed miscarriage. I cannot put the thought out of my mind no matter what I do. I try to have faith and try to find comfort in prayer, but I'm just so scared...anyone been where I am? Any help is so greatly appreciated.