What Is The Reason For Delay In Periods Even After Abortion?

i found dat i ws pregnant on 14 feb. i took mifepristone on 15 feb nite n two pills of misoprostol next day. after taking misoprostol i hd bleed after 1/2 hr. bleeding continued for 8 bays. clot ws also present in bleeding.my home pregnancy test ws negative. my 2nd period hs not yet started. is there any problem? am i still pregnant?