What kind of beer and what's the ABV? Is it possible to open, reprime, and recap? Yes. It is generally not advised though, because if you primed with the correct amount of sugar the first time you are going to be over priming the second time. That leads to bottle bombs.
As Revvy always says, three weeks at 70* is the minimum. It will be longer for bigger beers. Wait for the three weeks and like others have said, give it a few days in the fridge. If that doesn't work, come back for more potential answers. Good luck.