I'm on the Nuva Ring (about 11 days now) and had sex yesterday morning. We used alternate back up for the first week, but yesterday we did not. I found out today that I have a kidney infection , and I'm supposed to start taking antibiotics ("Macrobid 100mg"/Nitrofurantoin 100mg) to clear it up (this is round 2 of antibiotics, since round 1 a month ago didn't completely get rid of the infection). I do not want to get pregnant, and I don't know if I should start the antibiotics right away or wait a couple days. If antibiotics will decrease the effectiveness of birth control, then it stands to reason that sex <48 hrs ago along with starting antibiotics can't be a good conbination if I don't want to be pregnant. I'm not sure how I feel about the morning after pill, or even if it would be worth it. Any advice? Thanks.