What do Braxton hick contractions feel like & at how many weeks can you get them !

So I guess I had them the other night Bc I woke up in so much pain and my stomach was like that

tightening and releasing in your stomach very uncomfortable I was getting them at 13/14 for severe dehydration

They feel like your stomach getting really tight. And it depends I think I read that as early as 20 weeks but last year I felt them at 34+ and this year at 19 weeks lol