Most people dont even wait that long so congrats on that. I know I met my bf and slep with him like that next week,lol. but if you dont feel comfortable with it yet then tell her you want to wait until you can give her a romantic evening and then do it. At least that way you dont make her real mad and she will kinda be wooed by it and give you more time. Take her to a movie some dinner and be a real gentleman about it, then sleep with her when you feel the time is right. If you are ready then go for it, no harm in it.