I'm so insanely tired, could it be twins?

I've had 2 full term pregnancies, the first trimester has always seemed the most exhausting for me. I miscarried twice last year, and we gave it a year to try again. So now wer super excited at being 6w5d. But I'm drained! Like never before! I did read that the higher your pregnancy # increases your chances of twins, as does ur age, although I'm only 31, but still. I don't think being this tired and getting 9 hours of sleep is normal!