First thing first, your girl doesn't voice all her feelings in bed. Hence, it is your job to do that for her. I am not saying that go and ask her what is not working out for her but try and understand her feelings, her movements. Yeah, I know. It's not as easily done as said. Hence, for helping you out, here I have compiled a list of things your girlfriend absolutely hates in bed but never says.
Get ready for some enlightenment, people.
Spend some time on the foreplay, there is no need to jump to conclusion right away.
Drop your old game. It gets stale with time, so need of sticking to worn-out methods.
She may not say it but she will like it very very much.
Question her whether she likes something or not. If you won't ask her, you will never know.
Your performance does matter but your main focus should be on her.