Urologist or endocrinologist
A urologist
It varies as to where they are. This something to talk to your doctor about.
Immunologist.
It is suggested that one should start off by visiting the family doctor first, he or she can do an examination and if one needs a specialist the doctor can make the right referral.
Totally
Yes if there is bleeding out of the groin non-stop I would recommend going to a doctor immeaditly
Groin pain could be a warning sign of serious ailment problem. But groin pain could also be a warning sign for other things too. You should probably go to the doctor is the pain becomes too unbearable.
If the pain persists, you should definitely visit the doctor. The 'inguinal hernia', which causes groin pain, is the most frequent type and it is thus possible that you suffered one whilst exercising. The doctor will be able to use an ultrasound scan to determine if there is a hernia. Surgery may be involved to remove the hernia, to avoid further complications.
Getting kicked in the balls
If you are having pain in your testicles, groin, legs and sensitive scrotum then you should probably go see a doctor to be safe, honestly it could be anything and the safest option is to get it checked out.
What causes groin pains? I would say grow'n pains. I think and heard its stretching or pulling of the muscle. Like when you strain to have a bowel movement. That muscle you flex when doing so is your groin. It sounds like you've pulled or strained something which may or may not be your groin. Either way it sounds like its time for a trip to the doctor.
If you are overweight and just beginning to exercise, that may be the reason you are experiencing groin pain. Muscles that normally don't get used, then get used a lot, will typically hurt before they are "broken in" so to speak. But groin pain in general is not normal and you should consult your doctor if it gets worse or does not improve.