"had unprotected sex the day i was ovulating.  within 12 hours i took plan b.  five days later i had a bad backache and woke up with cramping and what i guess was heavy spotting that lasted about 3 days.  my period was due on a tuesday but started that saturday (5 days late).   the only real side effect besides the spotting was i was very irritable the week leading up to my period and i never ever have pms.  i would recommend this highly if you get yourself into a similar situation.  of course condoms, bcp, iud etc&hellip; are a much better option."