About sexual endurance?

So today my girlfriend of 6 months were finally capable of having sex without her experiencing any pain and actually enjoying it. We were at it for 45 minutes before we were forced to stop because we both had to go out. This was my first time and her first time the thing is i never ejaculated during the entire thing. We're both 17 and all my guy friends always tell me that they lasted like 3 minutes before they came their first time but i just never did. Also i wasn't using small motions i was using full length motions ranging the speed from fast to slow and nothing. is this weird or am do i just have good sexual endurance. Oh and if you're wondering about why it took 6 months it's due to the fact that i'm Dominican and have a lager than average penis while she is Chinese (i know interracial but it's awesome) and has a smaller/tighter than average vagina.