Is it okay to want to leave my gf?
What makes you want to leave her?
She won't shut up about birth control!
I don't think leaving her is a reasonable solution to the problem you're having.  You two should discuss this rather than you just up and abandoning her.  Hopefully you can work this out!
Fuck that shit. I rather be single than with someone who is fucking annoying.
Walking away from a relationship with your gf leaves her alone and without support. If you have issues with birth control then speak to her about it, but don't drop her because of this minor issue.