I am no expert, but I had a bowel cancer scare (sort of) last summer and did a lot of googling and from what I read, a negative FIT means bowel cancer is very unlikely. Adding in a clear rectal exam, your age and the fact that it sounds like you have no visible blood (?), I would gues the odds against it are astronomical.

My situation last summer was that I had rectal bleeding, trapped wind, weight loss and occasional loose stools (maybe once a week). I couldn't get a FIT because I'm in Ireland and scammers had hacked into our health service and it was in chaos. The specialist told me that as I was only 40 at the time, the odds against my having cancer were 100 to one and that I'd be "the unluckiest person in the world" if it turned out to be that.

You are significantly younger than me, don't have weight loss or bleeding and on top of that, you have a negative FIT, so your odds of cancer are probably a good deal lower than mine.

Stress can also bring on or exacerbate stomach problems, so it is quite possible the tummy aches and bloating could be related to the stress of the whole situation. It is unlikely there is anything seriously wrong with you.