I've been sexually active for about half a year, with only one partner who's away half the time. We used to use condoms for protection but i've been on the patch for a few months. We were together for the past weekend, having sex twice a day on average. A day after he left town I started experiencing frequent urination and painful urination. It's basically every 4 minutes or so I have to pee, but little come out. The frequent urination is constant throughout the day but does not happen when I sleep. Also, i've noticed little blood spotting during sex but not after sex or in urine. I'm scared to drink liquid so I've been dehydrated for two days now. No other accompanying symptoms present, no back/pelvic pain otherwise, no fever/headache, normal appetite, no abnormal odor/substance in urine. My partner is completely fine, no discomfort, hasn't noticed any abnormalities. Can this be a UTI or an STD(I)? How long does this sort of pain take to go away?