I was the same way when I was pregnant with DS2. I fell pregnant with him 3 months after losing Noah. DH didn't want me to find out the gender as he felt I would freak out like nothing else if I knew I was having a boy. I agreed. I worried constantly and the midwives & hospital were brilliant in calming me. Perhaps have a chat to your midwife and tell her your concerns. Remember, if you are worried, you can always go to the hospital and have a check up to put your mind at ease.
Sending massive hugs your way hun