Is Pregnancy Possible Despite Taking I-pill?

I had my last period on 13 feb then we had sex on 31 feb but I dnt ate ipill coz he dint ejaculated inside After that I havnt got my period yet nd we again had sex on 26 march at 1.30 pm nd I ate ipill on 29 march at 12.30 pm. Actually I hav a problem of irregular menses. So til wen I must get my period. Should I now go for ppregnancy. Can I get pregnant after having ipill We r very worried Plzz ans