Whats up bait it sounds like maybe the connection could be loose also. Definitely get someone to look at it. What happens is over time the connections get loose and they won't necessarily trip right away but as the load gets going the connections get hot and can create loss on the circuit driving the ampacity up. Definitely have it looked at by an electrician. I am one, and bad connections create heat and heat creates fire.

It could just be a bad breaker too but my money is on the loose connection.