What Could Cause Chronic Vaginal Itch Which Sometimes Causes Urinary Incontinence?

Hi, For the last 3 months every time i've had my period i have experienced an itching sensation down below. i have tried several different things in order to stop it itching. As I normally wear tampons whilst on my period, to see if it was them i have recently i been sleeping without one in. I don't bleed much when i'm on my period so i let myself breathe at night and that's fine. I have also worn a pad in my underwear to see if that helps. Although it helps if the itching becomes embarrassing, it doesn't stop it completely. The itching is on and off, most times constant but bearable, like a normal kind of itch, but sometimes it increases to such a level that it causes me to urinate for a short time beyond my control - hence the pads. Sometimes i can stop myself urinating, but i then have to practically run to a toilet to get rid of the itch. And every time its only a tiny bit, it also itches a little more as soon as I've stopped for a couple of seconds before dulling back down to the constant. A rapid change in temperature sets it off as well so i can't leisurely stroll from a car to the front door of my house and open the door at my own pace, i have to literally run and open it as fast as possible and go to the toilet as soon as i'm inside. its extremely annoying and i was wondering if youd have any suggestions as to how to deal with it?