I had 3 miscarriages, and the whole time during my fourth pregnancy I was praying to just reach 27 weeks because at that point the baby could survive outside the womb. Also, one thing I did that kept my nerves calm was invest in a home ultrasound to hear the heartbeat. Whenever I didn't feel much movement, I did it and was relieved. Also, at 25 weeks get a 3d ultrasound. Its cute and you get to see your little bug moving around and doing its thing.
It definitely keeps you going.