I hope you've gone to the doctor already. You probably have a bladder infection (a type of urinary tract infection or UTI). A UTI is not a sexually transmitted disease. It is actually very common in women because the urethra (tube that urine passes through from the bladder to the outside) is short and it's opening is near the vaginal and anal openings. A bladder infection is not serious if treated early with antibiotics. Make sure you take all of your prescription according to instructions, so you kill all the bacteria, otherwise the infection might recur and become resistant to the antibiotics. If untreated, a bladder infection can spread to the kidneys. Kidney infections ARE serious and can cause permanent damage to your kidneys or a blood infection. You should call your doctor immediately if you have nausea, vomiting, fever, chills, or pain in one side your back under your ribs (where your kidneys are located). These are signs of kidney infection.

If you are unable to get a doctor's appointment right away, try taking Azo, or something similar. It won't make the infection go away. It only treats the symptoms, like pain and the urge to urinate often. But it can help you feel better until you are able to get to the doctor. Just don't put off going to the doctor. Get treatment as soon as possible.

For the future:

Sex can cause bacteria to travel up the urethra to infect the bladder. Urinating after sex is helpful in flushing any bacteria out before they can cause an infection.