Extreme fatigue 😵😴

So for the last 3-4 wks I’ve had quite considerably high energy. Starting yesterday I all the sudden have extreme fatigue. In fact,last night I slept ALL night without waking up once!! To pee or turn over! I was so shocked when I woke up and it was morning! Now today I’m feeling the same way,just tired. Usually I’m going around dusting and vacuuming and tidying everything up. Is this normal?? I’ll be 41 wks on Thursday so I’m ready for something to happen!