Yes, it does happen, though it is very rare. One in a hundred VK users may experience this. Do not worry about it. If this happens, remove VK and try wearing it for only a few minutes a day. Then, gradually increase the wearing time of VK for more hours each day.
Alternatively, try placing VK in your pocket. After a few days, you can wear VK for a whole day or for a longer time. This gives time to your body to adapt itself to the flow of energy from VK.