27w pregnant pelvic pressure when walking and standing up for too long vagina seems to protrude out of vulva by end of day and feel leaks cystocele?

You may be correct: A cystocele is when the bladder protrudes through the vaginal opening and usually occurs in females after childbirth. This condition may also occur in athletes or after trauma to the area. A cystocele may be mistaken for large bowel or vaginal contents protruding through the vaginal orifice. Your description could be either of the above. See a gynecologist if the problem results in discomfort.