A pulling feeling in my vagina - 33 weeks pregnant

Ok so I'm 33 weeks pregnant and for the past few weeks I've felt a pulling sensation inside my vagina. I don't really know how to explain it.. kinda like if there's a few strings being pulled from the opening of my vagina all the way up. Seems to be getting more intense as time goes on. It doesn't hurt at all just feels really weird and I'm not sure what it could be.. anyone else experience this?