Is this happening to anyone else?

I'm 33 weeks 6 days and every time I get up to stand up and my legs feel like they are going to break from by my vagina. I've told my doctor and he says not to worry but the heavier she gets the worse it feels, it hurts to close my legs I only feel comfortable when laying on my back with my legs spread out. This will be baby #3 for me and I have never experienced this for my other 2, please tell me I'm not alone or if this is just another one of those joys of pregnancy 😩😩😩