I'm 8 weeks pregnant and I'm having trouble sleeping. I can get to sleep fine but every night I wake up around 4 for at least 2 hours then I spend the rest of the day utterly exhausted. I had this problem on and off before I was pregnant but found taking a herbal night aid would get me back into the rhythm of normal sleep. Are there any sleep aids out there that are OK to take while pregnant or is it not advisable?