You may not feel any psychoactive effects from the CBD if there is no THC in the oil. You may be getting the benefits of CBD without "feeling" anything.
If you want to feel something you may benefit from a 1:1 CBD to THC strain such as Pennywise, but take caution as the psychoactive properties can make you feel "high".
When you first start to use CBD oil with a vaporizer or a tincture orally it is best to start with small doses to see how little is able to work for you. This will help to ensure that you don’t take more than you need, and will also save you money by optimizing your doses.
I had a bad migraine. I took about 20 puffs on one before it really helped, although it started feeling somewhat better after just a few.