help explain!!

so I’ve been unable to pee for a few days like keep bursting for a pee but nothing comes out. I had unprotected sex last night and I have gone to get emergency contraceptive today. I have had unprotected sex before, my private parts are now VERY itchy and I am unable to pee again apart from some blood which was from the pill. Could this be like a yeast infection or what someone help?!! It is quite dry down there tho