I've been on generess fe for about a year and a half then last month my doctor changed my birth control to minastrin 24. I never had a break between the two. When I would have started my next pack of generess I started the minastrin. The first week and possibly into the second week of my first pack of the minastrin I was on ampicillin 500mg for a uti. I had my period then I started my second pack of the minastrin November 15th. I had intercourse the following Tuesday the 17th but it was with a condom. Say for instance the condom broke, would my birth control have been effective at that point after taking the ampicillin?