Restless nights?

Justice • son born 12-9-16👦 missed miscarriage 7-12-17 at 10 weeks👼 blighted ovum 2-5-18👼baby girl born 11-25-18👧
Hi there! I'm 6 weeks 1 day pregnant and recently I am sleeping really deeply to the point my husband has to wake me up or go care for our 6 month old himself. I have never had this problem. I also kept waking up during the night feeling extremely disoriented after having really intense nightmares. It happened maybe 4 times last night. Then this morning I didn't wake up when my husbands alarm went off and he went to have a shower. I also had black bags under my eyes for the first time ever. I don't remember being like this during my last pregnancy. Is this just extreme fatigue from my pregnancy? Is there anything I can do to feel a little more awake during the day and sleep better?