My first contractions felt like I had to have a BM, I went back and forth to the bathroom 4-5 times before I realized they were
contractions, as they worsened they felt
like an extreme pressure/tightening/cramp,
like a period cramp pressing down super hard (sounds crazy but you'll understand when it happens to you haha). When you go into labor you just get into that mode, you'll do great!