What Causes Nausea And Stomach Pain After Taking Plan B Pills?

I lost my virginity 4 days ago and we used a condom all but once and i let him stick it in twice for not even five seconds at a time then had him pull out because i didnt want to get pregnant. I took the step b pill once then we had sex again so later on the next day i took another step b pill. Now im nausaus and getting pains in my stomach but the side affects from the pill is only supposed to last for a max of two days... but that is only for one pill im confused and need some advice.