Weird Popping

I have had sex throughout my whole pregnancy and have never had a weird popping feeling while in certain positions until now at 32 weeks. The last 2 times me and my SO have had sex i was on top and there was this very uncomfortable popping feeling. It's never happened before so i know its pregnancy related but what is this?? How do I avoid it so i can have good sex again?? I have a hard time climaxing and being on top is the position that gets me going the most so this is unfortunate 😩