I’m a little confused can someone help?

So if I’m correct I got my period August 19th, I usually ovulate 10-14 days after. I got an ultrasound today an it says that the baby measured to be 5 weeks and 4 days. On the <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> it’s saying I’m 4 weeks and 5 days, and that I ovulated the beginning of September when I put the ultrasound and how many weeks the baby measured on a website it says that I conceived from August 25-29th and me and my husband didn’t began having sex until August 30th until now. I’m so lost