extreme fatigue

I just hit 30 weeks and have had an easy pregnancy so far. I’m just dealing with very extreme fatigue now. I went to bed around midnight last night and slept until 8am. I got up long enough to eat breakfast and was still super tired so I laid back down and slept until 4:30pm! I feel like I could fall asleep again any minute now. Yesterday I was pretty much the same way. What could be causing me to be this tired? Or is it normal? This is my first pregnancy so I really don’t know anything lol