I understand... This forum sometimes helps, but it also contributes a lot to create collective paranoia.
I think its better to be cautious with something like this than not. If I had read a post about a snapped leg I would have gotten mine checked out when the pain started, and saved myself some money and an awful, painful experience.
Just don't be ridiculous with it. If your leg pain is mild and goes away, its not serious. If pain is very consistent and lingering and deep just get it checked out and if its good, then push it from your mind. Don't obsess over non issues- and for most this will be a non issue.
If pain is super severe- play it safe- don't run, be conservative with walking, and DONT stretch it or apply pressure to the sides, where the bone is weaker- And get it checked out ASAP. Once severe pain starts is where you are in the danger zone. If it is mild, although you might escalate to a severe stress fracture shortly after, from over use, it is probably not going to abruptly snap unless it got smashed by a hammer etc.