Waking up early, can't sleep!

I'm a little over 5 weeks pregnant, I used to take unisom to sleep but stopped when I got pregnant, It takes along time to fall asleep. It's worse in the mornings, I used to sleep in until 9:30-10:30 am with no problem, since I found out I'm pregnant I wake up at 6:00 am and can't fall back asleep! What's causing this? How can I fix it? I don't want to take meds because I'm scared to screw anything up and my first doc apt isn't untill week 10. HELP!