I hav eblood shot eye and minor pain behind eye, what to do?

See a Physician: Without a photo hard to say. This could be something scary looking like subconjuntival hemorrhage, google image search, but really not dangerous. If the images do NOT look like what you have, you should go and see a physician.

See your eye doctor first: To determine what may be causing your bloodshot eyes, which could be as simple as a dry eye condition that needs to be treated with lubricating drops or, if it's something else that needs to be treated differently. The only expert who can determine this is your eye doctor. So visit your PCP first, and get a referral to see your eye doctor, unless You can call your eye doctor tomorrow and make an appointment.

Be evaluated: If you are having pain you should be seen. It could indicate inflammation inside the eye (irites) or elevated eye pressure. You also have a corneal problem, especially if you are a contact lens wearer. Sinus disease should also be considered.