28 weeks measuring 31-32

So it didn’t really sink in until I got home that I was measuring almost 4 weeks ahead and now I’m having a mini freak out after reading about it online (which I know is the worst thing to do). It’s my third pregnancy and my babies have always been big but I don’t remember if I measured ahead with my last one or not (it’s been almost 6 years). Since it’s now too late to call the midwives back I figured I’d check in here and see if anyone else has or is measuring that much different than what they should be and what (if anything) was the cause of it