What Causes A Delayed Period After Taking Unwanted 72?

i am 24 yrs old,married.height 5 feet,weight 56 kg.me and ma husband is not planned to have a baby now..once we contacted condoms got broken..then ran to a shop and ask for ipil..bt didnt get that instead gave another tablet..i dont remember the name of tab..its name is followed by 72..i had that within 2 hrs..usually i am having 28 cycle menustral period...am supposed to have periods on dis aug 6th..now its 5 days late i didnt have periods..am i pregnant??