L.I.
A.-
I am dealing with the exact same pain now (i'm also in my last month). I had it with my last two pregnancies as well. It is normal, and it will go away after you have the baby, BUT if you want it fixed now, or atleast the pain eased quite a bit, you should go to a chiropractor. Your pain is actually pinched nerves from your pelvic bone moving and stretching to make room for your growing baby. Once I went to the chiropractor, I noticed an immediate difference - an adjustment will do wonders and it is completely safe to do while pregnant.
I know it is really painful, and I hope you can get it fixed or have your baby really soon!
(just FYI - round ligament pain and placenta detachment you will feel in your abdomen area, even really low, but not in your pubic area and inner thigh)