It has all been said by others before, but here is my internet science. At one point in my journey I was told I had something called BCFS, and being as nosey as I am I investigated.
Benign Cramp Fasciculation Syndrome (aka Peripheral Hyperexcitability syndrome) is something that happens to relatively young healthy adults who enjoy a lot of physical activity and sports. In some people, a tremor will develope first followed by twitching later on. The type of fasciculations involved in BCFS, BFS ... are not caused by dying nerves trying to reconnect, instead it is more of a static discharge. Pent up energy in the muscle fibers. So, an EMG/NCS will be normal. Another thing I read said that if you move the muscle while it is twitching, it will probably stop. Also, I did read one article that questioned a correlation with ADHD, and of course, if you worry excessively, it is suppose to be a good fit.
Stuff happens to us over the years that cause us to worry. That is normal. Your PCP is your best bet to explore possibilities.