Hi, I am currently on Yaz birth control since a little more than 2 weeks. Have been taking a pill a day with no more than 3 hours apart (everyday between 8am-12h30 pm) took the first pill ever at around 10:30 am. I have been on nitrofurantoin since the end of December since I am prone to urinary track infections. My doctor made no mention of it reducing the effectiveness of my birth control were I to start taking birth control (which we have spoken of in Late December as she prescribed me the low dosage anti-biotic that I was to take for a couple of months every time I had sex and there are about 50 pills that were prescribed to me). Yesterday, I had sex with my boyfriend, he pulled out before ejaculating and even though I was on the pill, I didn't use protection and took a nitrofurantoin pill right afterwards. My 2 questions are, does the pill I am used to taking after sex reduce the effectiveness of Yaz and my 2nd question is: If it does, what should I do at this point (It has been more than 24 hours since I have had intercourse). Thanks a ton!