Is this contractions/ Braxton hicks?

I'm 36w1d and my legs are ALWAYS SORE. I'm a tiny girl, I was 105 pounds pre pregnancy and I'm now 145-150, I literally waddle. Walking too long or standing too long is a constant struggle and painful because I'm just so heavy. Also the second I stand up I feel like I need to pee even when my bladder is empty. But anyways.. I have this sharp pain in my inner thighs, also kinda by my vagina that just kills, especially when I move my legs.. it feels like pulled muscles but I know they're not. Just painful cramp like feeling. And I'll get the pain in my back and hips too.. It's odd, never experienced it before. Along egg that I've been cramping a lot lately. I just assumed it's all due to the baby coming soon. Has anyone else experienced this or know what it is ?