What Is Causing My Chest Pain?

Hi, i was feeling very tired and sluggish, my concentration and co ordination were poor, i started to take sea kelp tablets 1 three times a day with meals and though all the other problems dramatically improved i have chest pain, not what i call severe but nagging, i take clopidogrel once daily after a t i a, though heart tests found nothing so this was a possible hemeplegic migraine i also have a g t n spray to alleviate the pain, or is it really just stable angina