I have a watery yellow-greenish discharge(booger like). 1st time. my period is due this week. i feel no pain or itch or discomfort. std? or pregnant?

Discharge: You could have a bacterial infection. You need to have this checked out by your doctor right away.

See doctor: This may be a vaginal infection. I suggest you see your doctor to be examined

Infection: Your description sounds like infection. See your doctor for cultures and treatment. If you are concerned about pregnancy be tested for that also. All the best!