Never Orgasmed

I've been married three years and have never had an orgasm. I've had a baby almost five months ago now. I don't like to masturbate. My husband is super sweet and totally disappointed in himself that he can't seem to make me orgasm. I feel like something may be wrong down there. It feels really good when we have sex so I'm not totally void of feeling lol! We recently bought a vibrator and he'll use that and that gets me going but I still never orgasm. Any tips or recommendations on how to? I desperately want to!