Why would DR Give me antibotics?!

Why would DR Give me antibotics?

I went to the dr to check to see if i had a UTI cause i have the symptoms of a UTI/Kidney Infection and the DR said there was no infection but she gave me a prescription of antibotics for two days. I am suppose to take 1 twice a day.why would she give me medicine if i had no infection?

1 week ago
no strange smells and this is what she said " Hello, How are you?", "we checked your urnine, and there is no infection at all, your urnine is infection-free"

1 week ago
No fever, My temp was 98.9

1 week ago
She gave me the medicine the same exact day I went in and it was the same day she said I had no infection.

1 week ago
I'm just really afraid. I'm afraid of what i might have if i have anything.

1 week ago
it doesnt turn my pee orange it's called
sulfameth/trimethorprm 800/160 tabs it's take 1 tablet for three days my mom said it was for two but it's actually for three

Sometimes the infection doesn't show up on the routine tests, but on the cultures which are read a couple of days later. She did that because your symptoms indicated you probably actually had an infection and she wanted to get a head start on the treatment before it got worse. If an infection shows up on the cultures, they will call you to give you additional medication.