I can give an "estimate" but I really don't know because I never keep track.
But if you are certain the date has never changed, that helps.
Why were you trying to have a baby with someone who lied to you a lot?
Also, she did a ovulation test 5/26 which was positive.
I found were a positive ovulation test could mean positive pregnancy as well. If there is a decent chance based on EDD of 2/11, then I would like to press her a little harder to get the noninvasive DNA test now. I feel the EDD is accurate because it was confirmed by a mutual friend and probably done around mid July.
The previous periods that I have were 2/13-17, 3/13-18, and 4/8-15. Do you think based on this there is a chance I could be the father?