Orgasm vs further?

So my boyfriend always feels bad about not finishing me but I'm not sure how to tell if I've come or if I've ever been close so I have told him not to worry because he always finishes first I just don't know how to tell for me or anything? 
Edit: we've had sex quite a bit and he has fingered me but when he does finger me it feels like it's too much for my clit when I do orgasm so I never know to continue when it gets intense like that...