So tired

So these last couple days I have been finding it very hard to get up for work. I sit like a zombie through breakfast as I am so tired. I haven't changed anything about when I get to sleep and wake up. I was also so hungry this morning, I felt nauseated. AF is due on the 15th, tested yesterday and got a BFN. I'm not getting the preggo symptoms like others on here. Could this be a sign? I'm gonna test again closer to the 15th but just wondering.