How do I know if my belly fat is related to stress?

I’ve been working out 4 or 5 times a week for almost 2 years now, and I have been doing intense ab workouts with my routine. I have toned up, but not as much as I would like to. Can the access fat around my belly be related to stress, how would I know? I do not eat fattening foods either. Could it be my workout is not intense enough? What can I do? Please do not answer unless you are a personal trainer or expert of some sort. Please help! Thanks!!