Ran the F8. Yup, this turn we gained an extra pop, and our religious menu shows a jump from 13% to 15%. F8 shows us with a total 15.22% world population. So question solved, simple.
One little issue I'm not sure sure about. Our total score jumped 7 points instead of 6 this turn when we grew 1 pop. I am not sure where the extra digit came from.