Just a question

I have read several women's posts on here who thought they might be pregnant because they "didn't feel like their period was coming".. I'm just curious as to what exactly that feels like. I'm not trying to have a baby but I'm not trying not to either, I'm supposed to be starting my period in the next few days but I've been having symptoms the past week that I don't normally have when my period is on its way. Does anyone have any input?