Am I broken?

Kelp • Dream big darling. And remember you are enough.
So when my and my boyfriend have sex I get an orgasm. And my body shakes and twitchs but nothing comes out. Until like hours later. Even when I masterbate. Is this normal? How can I actually cum? Because he feels like he doesn't do a good job. Some people have said that I don't have the muscles strong enough to actually push the cum out?? I'm not sure. Help.