According to glow I start my period tomorrow

According to this app I start my period tomorrow but I have a feeling in my gut that I won't. Usually I show signs like very lite cramps a day or two before I start but I haven't gotten any. I also have sore nipples and been snacking quite a bit but I also know that, that can be a sign for your period to show up. I guess the reason why I am posting this is because I want to know how many of you just get a feeling deep down in your gut that your period isn't coming and end up being pregnant??