I took plan b one step Dec 4th, three hours after condom breaking, it was during one of my fertile days, my period is supposed to start dec 18th, I took a pregnancy test the 13th and it was negative, took another first thing this morning (the 16th) it was also negative, I've heard certain sites that the test doesn't work until a week after missed period? Is this true and could I be pregnant, does plan b not work when you are h.fertile? Thanks.