can anyone relate and help?

So I am not pregnant blood test came back negative but I have hot flashes and my period is 13-14 days late. I'm tired. Hungry and more. So what could b going in that would prevent my period n make me have hot flashes? I am only 31 so hopefully can't be menopause. I'm never late for period. Just wondering if anyone has been in this position n figured out what it was. I am making a Drs appt Tuesday but they prob won't b able to see me right away. I'm just so frustrated as I want to just b able to move on ttc and sick of feeling this way.