Ranked points L.P

I dont understand 1 thing, I rank upped from Brzone IV to Bronze III. I lost one game and I had -3 LP. ye you are rgiht -3LP.Than I won 1 game in final screen it said:+22 LP, and when I spectated my profile I had 9 LP.Than I lost again and I had 0. WHAT?!

Thanks for respond,Marek144Sk.