How far along are you.... If youre coming closer to your due date it can be from the babys head facing down and pressing on a nerve which causes that sharp shooting pain in your vaginal area. Google 'lightning crotch' - thats what some midwives refer to it as x
If its in your pubic bone its probably the ligament stretching.
It could also be separated symphysis..I had it with my first pregnancy! Before birth its most likly a miss alignment of the pubic bone, after birth its a separation of the pubic bone..ask ur doctor to check it for you..and yes its painful! ! Feels like your getting stabbed when u try to walk!! You can try going to a chiropractor that works with pregnant women it could help re align your pelvis and relieve pain or try soaking in the tub !