If you've gone two weeks without smoking, then you have crossed the hurdle and should be able to go the distance. That said, some of us have trouble getting over the attraction of smoking until we realize how much better vaping can be. Lots of us cut down drastically the first week, but still held on to a few cigs for a long time. What we discovered is that smoking a few was just a crutch that we could have thrown away any time we wanted to.
For those of us who found the habit hard to quit cold turkey, keeping a few cigs a day for a while helped us compare and decide we didn't need them anymore. It didn't take long for me to decide that cigs tasted crappy and my ecig tasted good. A while after I started vaping, I decided that I didn't need the cigs anymore. At that point, I had re-adjusted my need for tobacco to a point where I quit and had no withdrawal symptoms. It was more of a natural progression to quit in stages than do it cold turkey.
The point? Quitting is the goal. Whether you do it cold turkey or in stages is the difference. Some drop cigs and never look back. Others need to hang on to a few and drop them gradually. What matters is that once you quit, you are convinced that it was a good thing for you. The mental part of withdrawal can be as bad as the physical. If you fail, just drop them in stages. Don't worry about it. You will eventually stop smoking ALL of them and feel good about it. Ecigs just help you control the urges until you are balanced mentally about the change.
It's easier to quit a half pack a day habit than a 2 pack a day habit. If you have to become a half pack smoker for a while to adjust, there's nothing wrong with that. The goal is to become a non-tobacco user.