Might be ciatic nerve. Not sure though cause I'm only 20 weeks. But it sounds like what my sister in law described.
I'm 36 weeks and I have so much pain in my thighs and legs and pelvic I can hardly walk. It's crazy. This is my 3rd pregnancy And I don't remember having this kinda pain with my last 2 kids ! Your not alone!
If its just one leg probably ciatic nerve. Ive been dealing with it since 15 weeks. Its from the way hes chillin in me... :/ im also 37 wks