I'm 21 years old and i missed my period last month with 2 neg pregnant tests. any suggestions?

Well: Its called secondary ammennorea if you miss more than 3 months. If on the pill u can not bleed during a cycle; sometimes people don't ovulate to create the right hormonal changes for a period. It may be a one time thing but if persists you may not be ovulating regularly. Physical or mental stress or weight gain can be related. Check preg test again, see doc if persistent issue.