I've been on suboxone for 3 months and today about 2 hours ago i started having the worst chest pain ever! what could this b?

See your doctor: Go to urgent care or er. There are possibilities of respiratory or cardiac issues associated with Suboxone though it is unlikely to occur unless you have had a recent change in dosage. It could be something as simple as indigestion or anxiety, but any sudden onset of chest pain should be evaluated immediately.

Chest Pain and Bup: Chest pain is not a commonly encountered symptom in those on Suboxone treatment, especially in individuals who have been maintained on the same formulation & dosage for months. Other unrelated etiologies should be evaluated for. Respiratory distress causing chest pain in this setting is unlikely without associated respiratory signs/symptoms (eg shortness of breath, alternation in breathing, etc).