So i had this ultrasound done earlier in january. My first day of my last period was dec 7th, i ovulated dec 27th (peak opk this day), i got my positive jan 7th, and a couple days or so later i had this ultrasound. The doc said its measuring for around 5w5d when i had that ultrasound done. But i ovulated late? Glow is saying i should be 8w5d right now based on my last period, and i have my initial appt tomorrow at 1015am, idk what to expect, someone said to go based on my ovulation date, which means id be only 6 weeks, and i think thats way too early to get an ultrasound done. Anyone else ovulate on or around cd21? How off was the estimation of last period vs how far along you actually are?