Hi, I Am A 23 Year Married Woman. Last Month

Hi, I am a 23 year married woman. Last month I had urinary tract infection during my periods (15th - 17th June). So I had taken lots of antibiotics and medicines during that period. This month my periods are delayed. Its 23rd July today and still no sign. I had 45 days cycle before but from Jan month I was on some PCO MYO pills till April and it became normal 30 days cycle. Can you possibly tell me what should be the reason of delay.