"ok... my bf and i had sex unprotected during ovaluation and i do not use bc. so , the chances of me becoming pregnant are reasonably high. and at the time i was taking amoxicillin bc i was getting a root canal so my dentist prescribed for precaution of infection. docs say that you can&#039;t mix these two drugs bc plan b won&#039;t work but i hadn&#039;t been consistent bc of the amoxicillin side effects and stopped taking it about four days prior to using plan b. i was a nervous wreck bc i thought plan b wouldn&#039;t work. long story short it did work !!! i took plan b the same day just maybe 4/5 hrs after unprotected sex. i was lucky enough to not have any side effects of plan b and my period came right on time today (almost 2 wks from taking the pill)"