Burning sensation and bleeding when urinating

I am 17 years old and have a problem. I have recently have been going pee about ever 15 minutes and can not hold it at all. Alot of times its nothing but sure feels like it, but when I do go it burns terrible and there is some blood in the urine. I have sex with my boyfriend twice every weekday and 5-7 times weekends. Could this be why???


I am also a week late on my period.