I didn't get my period for a month and now having pink discharge and a negative pregnancy test and still no period. what is going on?

Many things: Many things can cause this including polycystic ovarian syndrome, insulin resistance/diabetes, thyroid disease, some medications, stress, changes in weight, diet ,exercise, or schedule, and pregnancy ( unlikely with a negative test). See a doctor for a full physical and testing to find out what is going on. Hope this helps. Good luck.