Help with conception date?

Hi all. So I’m just a little confused and was wondering if you guys could help me, I’m trying to figure out.

I’ve had regular 29 day cycles.

So, my last period was May 17th

Due date based off ultrasound: February 23rd

Due date based off last period : Feb 21st.

Online charts say I conceived either May 30th, May 31st, June 1st.

What are the chances I conceived June 12th?

I found out I was pregnant June 22nd (10 days after using preseed) I was 5 days late at the time & my HCG levels were 555.

I’m just trying to figure out if we actually got pregnant naturally or with pressed. We didn’t use preseed UNTIL June 12th. So just trying to figure out. Thanks so much.