I feel like peeing???

Okay so whenever I have sex, at points I feel like I have to pee. I don't know if this is normal or not and I don't know what to do about it? I've been told "oh its probably an orgasm or maybe you're gonna squirt just let it happen" but I'm so afraid to just relax myself and let it happen because I'm sooo scared I'm going to literally pee on them. It's to the point where I can't really enjoy the sex cause I'm so focused on not peeing... what does this mean? And what should I do?