Due Date?

The due date has been an elusive game of "pin the tail on the donkey" for Matt and I since day one.  Based on my knowledge of my own body, when I started throwing up, and of course conception date ideas, positive and negative pregnancy tests...I placed my own due date around the end of August. 
I have never been "regular" so you can nix the last period schedule for the due date.  Apparently you can share possible conception dates with your practitioner, but this has little bearing on the due date or something...?  They haven't seemed that interested.
We had an early ultrasound to date the pregnancy where they told us we were at 7 weeks and a few days putting the due date at September 16th.  I never liked this ultrasound.  The tech was rude and wouldn't show us the screen or even tell us if the baby had a heart beat (some rule about only being able to have a radiologist read it and give us the results).  She only showed us the screen after I started crying and only for a second "here's the baby...here's the heart beat."  Not to mention she chewed gum that sounded like a cow with its hoof stuck in the mud the ENTIRE time.  Anyway, this put the date of conception at least 2 weeks after I started with the nausea and other pregnancy symptoms.  And the date of conception only a week and a half before the home pregnancy test.
Then there are the other signs of due date.  I measured high early on.  My nausea symptoms resolved earlier than the literature I read said it would.  My 20 week ultrasound measured the baby's due date more to September 6th than the 16th.  I dropped nearly 2 and a half weeks ago.  Some of the very "late" pregnancy symptoms have been going on for 2 plus weeks.
So when does this put my due date?  Who the heck knows.  We are just trying to be patient and wait for God to decide my little Peanut is ready to come out.  It could be nearly October...I would explode...but it could be.  It could be tonight.  He could be two weeks early, he could be right on, he could be 9 pounds and a week late.
We certainly don't know.  But this is our first test in patience as new parents.  Definitely not the last time our patience will be tried by this little one.