Diarrhea and itchy vulva at 37 wks pregnant

At 37 weeks, loose stools can sometimes be the body's way of preparing for labour, but the itchy vulva on top of that is worth flagging to your gynae rather than waiting for the next scheduled visit, since it could be a yeast infection or something else that needs proper treatment. I would not rely on home remedies for these two things together at this stage of pregnancy, just to be on the safe side. Most clinics are fine with you calling in between appointments to check if something needs earlier attention, so it is worth giving them a ring and describing both symptoms. Better to get a proper assessment than to guess, especially since you are so close to your due date.