My girlfriend and I went to planned parenthood a month ago. Her period was supposed to start about 3 days after she got the pill.
She started taking it 3 days before her period.
She hasen't had her period since.

She took the pregnancy test (more than once) and she isn't pregnant.

Question is, the pill packet - Desogen - has a row of green pills, and they are supposed to be for your period. What do you do with them? Do you take them to start your period? Or you take those ONLY when you are on your period?

The doctor should have given her detailed instructions on when to take which pills, etc... she will have to talk to them to find out as her pills may be set up different from other people's pills. It is important to note that the pill does not start preventing pregnancy right away, though, so until you two get her pill situation figured out, I would suggest that you continue to use condoms or some other form of birth control to be safe.