I have a hard lump (sounds ominous, doesn't it...) the size of a grape in the left-hand-side of my tummy. It's about an inch underneath and two inches out fom my belly button.
Went to GP, he said hernia, sent me to hospital to see consultant surgeon. Saw him this morning, he's sending me for an ultrasound. He said it's "most likely" a hernia, but he's not 100% sure because my lump doesn't hurt at all, and he couldn't push it back into place.
He said it could've been caused by my C-sections but that it was quite a long way from the scar.
I said, could I still go to the gym/ He said no, but that he'd make sure the scan appointment was soon - within next couple of weeks - so that it wouldn't disrupt me too much. ARGH! AN URGENT SCAN! 
I have no symptoms of anything! I recently lost weight and have gone mad in the gym, especially rowing, so could it be a hernia? I want it to be a hernia, not... Well, you know.