I am having the same problems. But also have a large lump right where my belt buckle goes. In 1 month i went from needing a belt with all my pants to unbuttoned just to feel halfway comfortable.
That my friend sounds like a hernia . Get it checked before you end up with bigger problems . I had one appear and on the advice of one of my customers at the time I saw a doctor one week later I had an operation to correct it . If you don't get it checked it can put you in the ground . I'm not trying to be an alarmist better to be safe than dead .
I agree with Bear....it may seem minor, but a hernia is your guts pushing through a tear in the abdominal wall.....it may be uncomfortable for now, but eventually it will get "strangulated" and you will learn what pain REALLY is.