Anorexics have similar,. critical self-perceptions. In some cases its called muscle dysmorphia. Our bodies, tissues, organs, etc. are in a constant state of flux. Calorie and water intake can affect this, as well as many other factors. I wouldnt worry about it, unless an underlying disease is the cause. Its normal for weight lifting males to be somewhat concerned about the size of their arms. The bottom line is genetics, you wont get any bigger than your DNA says you will. Perhaps your DNA is conversing with you.