This is my understanding as well, ie a unique human being with unique DNA is created at the moment of conception.
From a theological stance the Bible states in Jeremiah 1:5 God knew Jeremiah before He formed him in the womb (the early stages of conception) and the fact that Jesus Christ was spoke of right before His conception clearly establish a unique person with a soul is created at conception.
Here is the definition of the Hebrew term form "יָצַר" ."http://biblehub.com/hebrew/3335.htm
There is nothing new under the sun. All things are a recombination of past things. What makes anything unique is its specific recombination.
Are you certain that knowing "Jeremiah" prior to being in the womb is a reference to him as an individual prior to physical conception?
It sounds more like an expression of destiny or fate based on the real events that did occur, rather than support for what you are claiming. Given that it is the physical recombination of genes (as well as any copying errors) that make an individual unique.
At any rate, you do agree with my statement that:
"At conception there is the beginning of a human being."
If you agree, then why were you debating this?