I've had a UTI every single pregnancy so far and never felt any symptoms. I took the antibiotics anyway because it can cause problems during delivery if you have one at that time.
Every doctors visit I have they say I have a uti, don't know why, or how. I feel fine and I stay clean down there, but I just have elevated bacteria levels. As long as you don't have symptoms I wouldn't bother. I'm perfectly fine and so is my son.
I had an Urinary Tract Infection on my second trimester and I didn't felt any symptoms except that you are able to see the change in color of your Urine. If he prescribed you antibiotics drink them.
I had a uti and never knew until i went to my doctors and had to pee in a cup. I guess some people never have symptoms while some do.