What Are The Side Effects Of Emergency Contraceptive Pills?

i messed up my pill about 3 weeks ago so stopped taking it.i immediately had a very heavy and sore period.2 to 3 weeks later i had unprotected sex with my boyfriend.he pulled out and i also took morning after pill (although was sick at the end of the night) my period is more or less due soon,have been spotting brown stuff for about 3/4 days and have had vaginal itching for about a week..what could this mean?