How likely is it that i have an enlarged spleen if i have mono? and how to know if your spleen is enlarged? and how likely is it for the spleen to rupture if you take part in contact sports?

If you have mononucleosis, your doctor should have examined your abdomen to determine whether your spleen is enlarged. Contact sports probably are little risk for rupture unless the spleen is quite large. However, your performance is likely to be reduced anyway, so if it doubt, it's probably best to take a sports break until you have recovered. Good luck.