So confused 😑😣

So me and my hubby stopped using the pill In November. Periods were pretty regular after that... But I've skipped the past two. And now I was supposed to start Sunday (two days ago) and didn't. Took a preg test on Sunday first thing in the morning- bfn. I am now experiencing nausea like crazy- all day long. I'll randomly crave random things like coffee or ketchup but today the smell of someone's pizza in the break room almost made me barf. I've had some diarrhea (sorry tmi) and I'm flat out exhausted all the time. What the heck body?? What is going on??