give me advice thanks

Well

me & my girl friend are going good now until i relise omg i really do love and decided not to leave her since the last incident about the pregnacy. I really do love her but gues what i heard " i love you 2.8% " i thought wtf i love you with all my heart and this is what i get.

Now here's the problem we seem to argue alot now. And she told me just today what is left between us, so i didn't want to let go but what with her aways starting off a mini arguement about god knows and then it becomes big. e.g one time about our mum how she hates my mum and i hate her mum as well I know it stupid but we got over that. Now her ex came down and me and her right now not happy with each outher like p!ss, so today she said i m going to go out and have fun with my ex. The moment i heard that it hit the heart straight away ouch. Now I'm confuse i feel like leaving her and she does to but for some dam reason when i left her she begged e back and i begged her back and now she leaving is it like a game or some thing? I'm sitting here thinking and confused. OMG still have to learn for exam as well i think why now not during exam week.

Any advice would be great.