Can extreme tiredness be a sign of pregnancy? Like, really early sign?

My sister had a miscarriage in June and she said she was EXTREMELY tired and had a hard time waking up even only 7 days after ovulation.

I’m 6-8 days away from ovulation, and I am exhausted. I can go to sleep at 8 pm, and won’t feel ready to wake up at 6:30 for school.... I’m never like this.

HELP PLEASE