Determining due date... o day or lmp??

Sadie • Aria Marie • Holden Matthew • Baby 3 due July

I had my daughter in November, 2018 and have breastfed her ever since so I only had 2 periods before I got my bfp & they were definitely not regular... but we were TTC so I was <a href="https://play.google.com/store/apps/details?id=com.glow.android">tracking ovulation</a>.

The date of my LMP was November 28, 2019 but my opk peak was December 21, 2019... which leads me to believe I ovulated on the 22nd which was CD 25 (over a week after the usual 14 days).

I got a faint line on December 31 & a definite positive on January 1 (around 10 dpo).

If I base my EDD off of my LMP it’s September 3, but based on conception/ovulation it’s September 13. My first prenatal appt isn’t until January 13 so I’m just wondering what date to go by until I have an ultrasound? 😬