Am I Pregnant With Black Clot Discharge After Taking Contraceptive Pill?

i'm 21 year old unwed girl...i had sex with my boyfriend on 12 march and 17 march without any protection...12 was my last date of menses..i took a contraseptic pill on 18 and i saw some black clots from my vagina on 22 march till today morning....i'm scared....am i pregnanat...plz help...give me some solution...