Have you ever felt like this?

Of late, as in since last week till now, I have this unsettled feeling in my stomach. I am not able to put a finger to it as in why I'm feeling like this. It is like there's something going to happen; not necessary to me, but to my concern for sure.

However, I know I shouldn't be worried. It is not something that I should worry about. Don't you just hate it when you know and yet you don't know anything at all. Or perhaps I am just being over sensitive. It has happened before. Or maybe I'm just excited over the pilates class this evening.