What Causes Bleeding Two Days After Sex?

sir i had done sex with my bf without using condom n den i took unwanted-72 after 6 hrs. since i had it for the first time so lil bit blood came out during sex but now after 2 days blood is coming from. so is there any chance to get pregnant and can i get my periods normally?? pls sir reply me soon. sir i am 21 years old and my bf is 25 yrs. old. my weight is 43 kg and my height is 5 feet 3".