Instead if it is a tampon. will not stop you from urinating , A tampon is used to stop bleeding menstural cycle; You must be very young. They are to entirely different openings.
"instead" of posting here why dont you try a GYN forum. this forum is for hepatitis. although i pride myself with knowing alot about the vagina i can not help you in this aspect. just a thought why not go on birth control pills? this will stop you from bleeding at all. dont forget, take care of that it can get you many things in life!