Doxylamine
"My OB recommended this for my insomnia/racing thoughts at night in pregnancy. Took 25 mg and was out w/in 30 minutes and tired the next day. Cut down to 1/2 a pill and was much better. Haven't gotten a full nights sleep in 6 months and was losing my mind, it completely fixed that. I will say that if I don't drink lots of water with it I get terrible headaches but as long as I stay hydrated and give myself 8 hours to sleep I am ready and wake up right away with my alarm in the best mood I've had since the pregnancy started."