My molars hurt when I chew?

The other day, my bottom molars randomly started to hurt while I was eating a kind of unripe mango. I didn't think much of it, since I've had things like this happen before, and just figured it would go away. I woke up yesterday, and my teeth still hurt. And today it is the same. They only hurt when I chew. I know it can't be cavities because I've had sealant in all of my molars. Why is this happening? Please help!