Third baby, high risk

So I’ve never posted in here- I’m 11+2 with baby #3- I have had tough births which put me in the high risk category. I got to see the nurse for my intake appointment today and she made me nervous by telling me I’m measuring at 14-16 weeks based on feeling my abdomen- but I had an ultrasound done at 9+6 and they felt dates were correct. She gave me a couple of reasons- A) third baby and just big B) multiples C) too much amniotic fluid. I have another ultrasound Monday but I’m kind of flipping out. Does anyone have experience with measuring greater?! I’m so nervous!! 🤦🏻‍♀️