I am what I thought around 9weeks but I went to my first appointment and the doctor said my uterus…

I am what I thought around 9weeks but I went to my first appointment and the doctor said my uterus is measuring large could I be further along or at 9 weeks with twins or just measuring big? This is my second pregnancy but I never went through this with my first. I have been sick almost everyday, not necessarily vomiting but my stomach just rolls all day and I have no appetite. TIA