Embarrassing sex question

Hi everyone, I have an embarrassing problem. It didn't used to happen to me, but lately, when me and my husband are having sex, my crotch (not my butt) has been sucking up air and then when I push out it makes this horribly loud farting noise but it's from my crotch! It completely ruins the moment and frankly it pisses me off because it's so frusterating and I don't know why it's doing it. It happens mostly when we are having sex doggy style (sorry if that's too graphic). It doesn't really happen during missionary position, but we like to do different stuff. PLEASE someone help me! Am I the only one this happens to????