Pregnancy after IVF fears

Anyone else extremely scared of miscarriage? After everything we've been through and I'm finally pregnant and I'm just waiting for the ball to drop and something to go wrong. You read the horror stories on the discussion boards all the time and I am absolutely terrified this baby won't last, even though everything seems ok. I thought after it worked I would be so happy and not have a care in the world, and now I can't stop thinking that something is going to go wrong. Is it normal to feel this way?