Enlarged Uterus while pregnant

Saw my OB yesterday & she said my uterus was really big. She thought I might have more than 7weeks. She said maybe 12weeks. She did a quick ultrasound and baby was measuring on time (7wks5d) and it wasn’t twins. She said I should come back in 2weeks and get another ultrasound to make sure all is still well. And that my uterus is well used so that is probably why. I have been pregnant 5times in 5yrs. Three births & 1 miscarriage & currently pregnant. Should I be worried about this? 🥺