Orgasim Help

Okay so me and my partner have amazing sex. And I used to be able to orgasm(vaginally) so easy and even quick with him. I never have any problems getting turned on, we're very sexually intune but lately I havent been able to finish. It's super frustrating. I'm wondering if maybe it's a side effect of my birth control or maybe my needs have just changed? This has been going on for a few months now. I have no problem getting myself off though. Any ideas or tips?