Its . Its very common for women to get urinary tract infections during their first sexual encounters. The blood you see when urinating may be from your bladder rather than your vagina. If the condition persists, and especially if you start to have pain with urination, you should see your doctor and be tested for a bladder infection.
ITS . Its true at infections in the bladder can be the results of intercourse but usually not after one time the bleeding is most likely from the skin protecting the vagina , called the hymen. As it stretches it can bleed. If burning with urination continues or obvious bleeding when urinating see you doctor if bleeding continues after intercourse also see your doctor-remember to practice safe sex and establish a method of birthcontrol unless you are attempting to concieve.