I was prescribed cipro on a Wed and was on the last week of my active pills in an ortho-tri-cyclin birth control back. I had sex on that saturday night and took plan b the next morning I then had sex again a few hours later. my period is very regular and I was supossed to get it that following Wed (so I week after being prescribed the cipro) my period is a day late. Can Cipro make the Plan B pill ineffective? and was a still covered if I had sex after I took the Plan B pill?