Flat beer

I bottled my first batch 10 days ago. I'm concerned I didn't get the sugar mixed well enough. When I turn a bottle upside down I get very few bubbles when I do the same to a Budweiser I see bubbles rushing to the top. What should I do if the beer doesn't carbonate can I add more sugar to each bottle and recap or am I screwed.

 

I would let it go a while, and I mean a few months maybe, before making the choice to add more sugar to the bottles. If this is what you end up doing, it can be done using carbonation tabs (the ones that use multiple tabs per bottle are best so you can dose lightly)

What temperature do you have the bottles at? Often it takes 2-4 weeks at 70F, and then it is best to chill the bottles prior to opening or testing. Some of the co2 is in the headspace and will be absorbed into the liquid as it chills.