What’s going on?

Patient: I haven’t had my period in about 4 and a half months. i’ve been on jolessa birth control where i only get my period every three months, but i just stopped taking it about a week ago or so when i realized i missed my period. i haven’t really expierienced too many pregnancy symptoms, however i did experience dark vaginal discharge. i took two pregnancy tests about 5 days ago, but both were negative. any ideas what’s wrong with me?