What Are The Side Effects Of Emergency Contraceptive Pills?

Hi I m 22 yrs old..for two months I have been feelin bloated..in april I had unprotected sex but I took the plan b so I got my period but it was normal for 5 days and then again I had unprotected on may 9 and took planb on the 11 so I got it again but t was red light red and brown..soo I have had sex ad I jus got my period and the same thing again red and dark brown .what is it doctor?