Helllo,Urinary tract infection
can be divided to two types as symptomatic and asymptomatic. In asymptomatic infection you won't get any symptoms like pain in urination, increased urinary frequency, lower abdominal pain
.etc. So most of females specially during pregnancy
can have asymptomatic infection.
I can understand your concern on your 1st pregnancy but you have to understand that urinary infection can cause serious outcome. The drug prescribe for you is known to be a safe drug in pregnancy. So don't worry about taking medicine.
If you are still concern about it you can repeat another urine full report(UFR) and also Urine culture and ABST.
Taking fluid regularly, frequent urination
are some general measures you can follow.
wish you a good health