I feel like it's so early for this but I guess it's not abnormal to have them at 20weeks according to google I don't remember getting them with DD until I was 27 weeks. But I read that it's more common to get them earlier if you've been pregnant before.
It's funny b/c now I can definitely feel how big my uterus is! It's higher than I thought it was. My pregnancy book said the top of my uterus should be at my belly button but mines about an inch and a half above it! Must be another second pregnancy thing....