I have a very light and irregular period and whenever I take out my tampon I notice a little bit of light green discharge. There is a mild odor to it. Is this an infection?
Green can indicate an infection. possibly trichomoniasis.
See your doctor.
Agree with PP.
Green vaginal discharge is a sign of some kind of infection. Could be trich, yes, but also gonorrhea, chlamydia, bacterial vaginosis, or pelvic inflammatory disease resulting from some untreated STD. It could also be due to any other kind of infection, really.
The important thing is that you get it checked out and then get treated. Even if you could magically work out the cause of your green discharge yourself (which you really can't), you still need treatment, and probably antibiotics, which are prescription only. In other words, see a doctor. As soon as possible.