️lazy baby

Does anyone else have a lazy baby? It's like one day I'll feel her non stop and than for the next 1-3 days barley anything! At my 20 week scan she was sleeping the entire time, woke up for a few minutes and sucked her thumb, than went right back to sleep. She wasn't moving around at all. I have to go back for another scan in 2 weeks because she had her head budged up into a corner and she wouldn't move for the tech to get a good look at the back of her head. I don't know if it's just normal at this stage (21 weeks) or what. Anyone else?!