Hi I had sex with my bf Aug 6 and take postinor 2 (1St tab) on the same day night time and take the 2nd tablet the next day.. My period come Aug 11 ends Aug 16 and had sex to him again aug 22..that day I take again postinor 2.then aug 28 I start suffer from bleeding until now and stomach cramps.. What this mean? Is this the side effect? Is it serious?