The bible says God forms our human spirit within us. So in the sense of the provider of life, God knows every human from conception, from when God formed our unique human spirit.
Some folks think "before I formed you in the womb" refers to before conception, but that is an assumption. Before I formed you could refer to the time from conception until the baby is developed so that it would be viable outside the womb.
The bible provides at least three examples of folks being chosen by God for His purpose, David, Jeremiah and Paul, "from the womb."
Lastly the Bible sometimes tells us of God's plan for an individual before they are conceived, such as Jesus.
Another popular misconception in my opinion is God has foreseen every human life, and has chosen before creation, those He will save. This rests on the idea that God knows everything, past, present and future. Certainly God being all powerful could know everything past, present and future if He so desired. But the Bible says God declares the end from the beginning which means whatever He foreordains will come to pass, such as His prophecies because He will bring them about, He will cause them to happen. On the other hand, if God has decided not to know everything, He can create a purview where His creations make choices that alter the future within the limits He allows. We make plans but God directs our steps which means He limits our range of actions. Thus when Abraham took out the knife to slay his son, God said "Now I know..." God did not foreordain Abraham's action, He did not know what Abraham would do.
In John chapter 21, Peter says of Jesus "You know everything." But in context this refers to Jesus knowing everything about Peter, or perhaps more broadly, everything about the individuals Jesus encounters. But since Jesus did not know the time of His return, this statement does not support the idea that Jesus knew everything possible.
So that theory of omniscience is biblically flawed.
How about the idea that God has plans for our lives. Does this mean God compels us to live according to His plans or desires for us? Nope. If we stumble today, and do not follow God's desire, God will have a new plan for us tomorrow. God can intervene in our lives and cause us to go a certain way, but the idea that He has predetermined everything that happens in our life is unbiblical. Remember the story in Romans where God hardened unbelieving Jews to facilitate the spread of the gospel to Gentiles? If God had predetermined their lives, He would not have needed to alter them by hardening their heart to prevent them from believing.
May God Bless