If you applied for medicine only and have been turned down, you have a decision to make. Is medicine all you want? You can add one non-medical choice to your application before 30 June.
Extra and Clearing are further chances to gain a place if you do not have one. Unfortunately, very popular, over-subscribed courses like medicine are unlikely to be available.
If you do not obtain a place on a medicine course in this application cycle, you could take a 'gap' year (which you can use to improve your grades or gain some relevant health-related work experience) and reapply in the next application cycle.
Another option is to try to gain a place on a related course, for example, a science degree. You could then apply for a postgraduate medicine course after successfully completing your degree.