Oh yeah I know exactly what you mean. Really I think it could be anything, horomones (even not on your period because being a woman we are ALWAY having fluctuations), our sugars go up and down all day, sometimes even good food doesn't sit right, being tired, too much sleep, not enough water, too much caffiene, a headache, the list goes on. I think nonemets feel it too but don't pay it any mind, as we would pay no attention if our pinky hurt for a bit lol (ok bad example but you knwo what i mean lol) I hope this helps!
\"As soon as you trust yourself,you will know how to live.\"
Johann Wolfgang von Goethe
\"Do not anticipate trouble, or worry about what may never happen. Keep in the sunlight.\"
Benjamin Franklin