Why Does He Go Down

Chanelle
Me and my boyfriend have sex everyday but he seems to go down before he comes and in fact sometimes he just doesn't come and gets pissed off. He says it's not me and I get that it's like he's got erectile dysfunction but he's only 21. How is this possible? But now I'm thinking he can't get me pregnant Because we've been having unprotected sex for 6 months now and nothing! I know it's not me I got pregnant last year with my ex and I've had all the tests done this year at the hospital. What can he do? Or is it something I need to do?