I get regular UTIs and it sure does sound like you have one.
For me, it's pretty intolerable the moment it starts. It's a BIG deal if I have to wait six hours to get into a clinic. But, that said, I know other women have milder symptoms.
Here's my usual sympoms:
*Overall funky, headache-y feeling.
*Cramping in my abdomen.
*Tension in my lower back, but - and this is VERY important - no actual pain in my kidneys. You can test that by gently thumping your lower back, off on the sides - if it makes you scream, you should go to Emerg. right away, because you probably have a kidney infection.
*Visible blood in the urine, or on the toilet paper. Sometimes even blood clots. It's not constant - it lasts a few hours and then stops.
*Orange-y, strong-smelling urine
*Frequent urination (but of course I'm drinking more water)
*A burning feeling
*A feeling of urgency, like I've got to go, even if I don't actually have to
*A feeling that I'm not completely emptying my bladder when I do pee
*A particularly sharp ouch-y sensation right at the end of peeing
What do I do?
*Get to the doctor and get me a prescription of antibiotics. It sounds like your doctor is sure enough of your diagnosis that he's willing to skip the testing and just give you the antibiotics.
How do I TRY to prevent future infections?
*Always wipe from front to back
*Pee before and after any "action".

*Drink unsweetened cranberry juice (cut with LOTS of water) or mix whole frozen (thawed) cranberries into my fruit flavored yogurt.
*Drink lots of water on a regular basis
*Don't try to hold it - if I have to go, I find a bathroom. I don't wait.
*I don't take baths, I take showers
*I don't put anything "down there", like a spray or a douche. I rinse very well in the shower, to make sure I don't leave any soap behind.
*I take vitamin C
*And I avoid sugared drinks, like soda pop
That last one isn't usual, but my doctor thinks that part of the reason I get so many infections is because the extra sugar in my pee provides a healthy environment for growing bacteria. I've noticed that I tend to get them after I've been drinking a lot of pop, such as during a holiday.
HTH! And I hope this is your one and only infection.
