So I mapped out my run as being close to 15km but decided to run with a pedometer ap on my phone. Basically when I reached a point of around 5km I looked at the ap and it said I had only run 2km. In the end it marked me down as having run 100k feet and 7.1km. But at home I checked a bunch of run distance calculators and according to them the route I ran was around 15km. I know the route into town is at least 3km but the ap didn't show this as 3 km.