How Long Till I Should Propose?

I've been dating a beautiful christian woman for about 3 months and have known her for about 5 or 6. Everything is great between us and I could not have even asked for a better match. I am having a dilemna though, I want to be able to make love to her and not ruin my own christian values but this burning pion inside is making me slip. Not that I only want to marry her to have , I am so in love with this girl and never thought I would want to get married again, EVER! She makes me want to. So what to do? Just do it? Wait? Hmmmm...