Yep, i think it is wise to see your MD for that. It could be bacterial infection of some sort. It may have been due to too much abrasion during sex. Are you circumcised? If not, it could be your loose foreskin that gives you your problem. Your doc may advise you to get a circumcision.
i agree u shud get a check up, it cud jus b a bacterial infection. but defo get a check up wud be benificial incase it is an std.
I would see a doctor. It can be an enlarged prostate possibaly due to an infection. Have you noticed any discharge? If not, I doubt it's an std, but still requires a check up.