It could be a lot of things. It could be anxiety, hormones, your new med.
When I ovulate, almost without fail for about three days, I wake up at 5am. No matter what time I go to sleep. I've been taking abilfy for a week and a half and now I wake up at exactly 3am. Lol.
Give some time for the med to take effect and see if it goes away. In the mean time go to sleep an hour early. When you wake up do some boring things: 15 minutes of a boring movie will do. Don't watch in bed, try not to turn on lights. After 15 minutes try to go back to sleep.
Most of the time this works for me.