Braxton hicks?

I’m 21 weeks. My lower stomach was feeling achey and uncomfortable. I think I’ve had this feeling before recently too but never thought much of it. But it just hit me - are these Braxton hicks? They are pretty mild. Doesn’t feel like cramping, just an uncomfortable achey feeling. It went away now. This is not my first pregnancy. I never noticed Braxton hicks with my first - I actually didn’t even feel my contractions til they got bad. Are these Braxton hicks or no?