Fatigue

I had to take off Thursday and Friday due to a family emergency. I had Saturday and Sunday off and I took those days to catch up on some rest I have been working Monday to today so far and everytime I get off of work I am exhausted or in the middle of the day I get really hungry and tired. I took a pregnancy test on Monday and it came back negative I just got done ovulating. I'm not sure what's going on. 😔😔😔