I had mono for a week. it has been four days since my symptoms have faded. if i try to play sports too soon is there a possibility that i will relapse?

Check with your: doctor but I would advise you to wait a few weeks before sports activity.

Relapse ?: I doubt that you would relapse, but you may find out your mind is willing but your body is not. You would also be at some risk if your spleen were enlarged (common) making it susceptible to rupture if you fell down or took a hit.Most adults take 2-3 weeks to bounce back with this.Some guidance with a physical exam would be wise.