January 22 due date, conception question

JH516

Out of curiosity, anyone else around similar due date know their date of conception?  My LMP was April 10 and I've been going off of an estimated conception date of around April 17th (conceived naturally) based on the baby's gestational age from early ultrasounds.  My cycles are avg 35 days.  I was on pregnology.com that said my conception date was probably May 2 based on the due date and it totally threw me off because it doesn't match the baby's gestational age.  Just wondering if anyone else is getting different dates and is totally thrown off.