Will urinary infection antibiotics delay periods?

Not really: While any stressful situation can potentially disrupt a menstrual cycle, antibiotics will not have a direct effect. Most antibiotics can potentially interfere with oral contraceptives so in that context a delayed period might represent a delayed (breakthrough) ovulation or even a pregnancy.

No: Typically it is not the antibiotics but the infection itself which can cause the hormonal variation at times thus leading to alteration in the periods.