What and why?

I have been getting so nauseous more and more with each passing day. It comes randomly and I only can stand to eat certain things. Just about any food sounds nasty to me. Even though I got negative blood tests and urine this past Sunday, I'm thinking I was too early for the tests to pick up the HCG hormone. According to my glow app I ovulated on the 30th but then it switched up and changed it to the 2nd of this month which I don't believe. My sex drive usually increases when I'm ovulating. And that would have been 8 days ago. Thoughts? I am currently 8 dpo