Pain During Sex Followed By Bleeding, Lightheadedness. Had Rough Sex. Is It Worrisome?

Hi. this is a little embarrasing but anyway, i had sex last night for the first time im maybe two or three weeks. i think that maybe it was a little rougher then usual but not majorly so, when i woke up this morning i noticed blood on me and on the bedsheets. it was enough blood to freak me out. now my period only finished three days ago but that has never been an issue before. i usualy do feel pain at the start of sex, but i just assumed it was a loosening out issue. . sometimes i do feel a weird pressure inside so i stop take a brake for a second and them im fine again. i never took any notice before but now im worried. i v seen some peoples comments on this but they all say they had only a small amount of blood. this wasnt really that small. i was also a bit lightheaded afterwards lastnight. i didnt say anything to the lad id slept with and he didnt bring it up. i dont know whether to be worried or not . . .