It is a false belief that girl should bleed at the time of first intercourse and if she does not, then she is not virgin. Virginity has nothing to do with bleeding. This bleeding occurs as a result of injury to hymen (delicate skin in vagina). Injury to hymen and its breaking can occur because of many things and intercourse is one of them. Your uncle is ignorant about this fact. Ask him to read any sex education book, all of them must have mentioned about this. Question I will ask to myself is, if I would have been in your place; why the hell I should tolerate this and continue sexual relations for four long years! Why you need to give any such certificate of virginity to a person who has sexually abused you and not trusting you. I do not know under what circumstances you have developed this relation but you have to think about continuing such relationship.