For the past week and a half, I've been waking with nausea, and throughout the day, I am unable to eat, I also have a strong fatigue feeling. I don't believe I am pregnant because I have had my period this past week. Should I see a doctor?

You could still have your period when you are pregnant. You should see your doctor and have a blood test done and if you are not pregnant you might be anemic.

Yes, you should see a doctor because you might have low blood sugar. I know that when my sugar drops too low I get nauseated and have trouble eating.

I would say yes, you need to see a doctor. This is very common with blood sugar disorders.