Level and base health not being what the website says it should be.

I've been playing the game for a while and would generally have the same health as the people I faced. Eventually I started climbing the ranks and fighting people at level 19-17, but their health started to drastically overpower mine, I'm still at 12 health while facing people with anywhere from 13-15 health. so I looked it up and saw that it's tied to level, only thing is that I'm level 12, almost level 13 and according to their website I should be at 14 health not 12. anyone know what's up or if this is a bug or something?