About two weeks ago,i had intercourse and the next day i spotted some faint blood in my urine. I found my self urinating every 15-20 minutes, it was stressful. I drank a lot of water, it got better next week, i thought i was fine so i had intercourse again on friday ( which would be an exact week ). I feel pressure when i urinate now -- don't know where it's coming from? The clitoris? The pressure came back, and i urinate alot again. i'm drinking water. Would this be a cystitis? or UTI infection? Or does it have to do something with having intercourse?

Please keep in mind that i am a teenager and my parents do not know that i am sexually active. Much appreciated!