"I feel like saying something to her right now, I should say it."
*Uuuuh, hey, babe, wanna get laid?
Obviously, you don't come up to a hot girl on the street and ask her to have sex with you. If you want to do that, you're obviously insane(or very confident). Instead, ask yourself not what you want to get(sex that is), but what you want to say when you come up to her. I highly doubt that you'll come up with "do you want to have sex?". I hope you're getting my point.
The right way to approach things is not to think about the future AT ALL, it is hard, but possible.
AT ALL, means AT ALL. Your D'oh means that you're trying to predict the future again.
You need tender loving care once a week - so that I can slap you into shape. - Ellyn Mustard