popping sensation?!?!?

Leah

Ok so I'm 37 weeks and I've been contracting for a cpl days now (been to dr just contractions no dialation still waiting) but I'm trying to rest sitting in bed and I went to position my legs and had a "popping" sensation in "there"? Like popping your fingers or something but on the inside.. no gush of fluids or anything just a pop and more contractions. Any ideas?? just kinda weird...