Any answers here TMI

Qu

Hopefully someone can make sense of this.

My period usually starts on day 25 or 27 and here we are day 31. I’ve had extremely soar nipples, yesterday and today I’ve been nauseous and my fiancé says that I have felt different during sex. I took a clear blue digital pregnancy test day 27 and 28 but they both said not pregnant. I’m at a lost I want to believe I’m pregnant but I’m confused.