My ob/gyn says everything is ok but i see light green/yellow fluid on my pants time to time.what can it be?doc doesn't see anything worrisome.

Green yellow fluid: If you have had a gyn check and everything looks normal, then these colors are most likely due to the metabolism of very small quanties of blood, perhaps left over from your last period, due to rupture of common small cervical cysts, or due to increased bleeding with periods from fibroids. If you have had the exam, i wouldn't worry.