It depends on the style and whether or not I did a cold secondary, but my beers usually start having some slight carbonation to them after about 4-5 days in the bottle, and are nearly fully carbonated after about 10. I rarely get green flavors because I let the beers bulk age (usually by doing an extended, 3+ week primary) before I bottle them.
So go ahead and give it a shot - it can be very educational to taste the beer throughout its evolution (I even have taken to drinking the decanted "beer" from my very lightly hopped yeast starters - not half bad, sometimes).
Just don't stress if it tastes funny. More likely than not, it will improve with time. My one suggestion is to put the bottles in the freezer for about 45 minutes and then transfer them to the fridge for another day before popping it open. That pretty much shocks the yeast and causes them to drop out of solution, reducing the "yeast bite" that some people refer to as the typical "green beer" taste.