Genius the backround of my big question

My big question is are we reincarnated,
Like did we live in the pass and we have no idea about it ? People say when they die there is a "light in the end of the tunnel." What if the light  is to another hospital room, and the reason we come out of the womb crying is because you remember everything from your past life and you're crying at the fact you died and lost everything. As we grow older we have this thing called "Deja vu" and you feel that you have done  a certain things before, maybe you did but in your past life. I did research and some theory are that a birthmark can be a sign of past injury or how you died in your past life. Another theory is that all of us have a spirt inside of us and after death it takes us to heaven or hell. If you do good deeds then you live eternal life in heaven, but God gives you a second chance to do things right on earth  so he sends you back and you are reincarnated, to make good deeds. Another theory is that once you die you reincarnate as an animal to make sure to erase all memory of your human life. However, there is also a  theory that humans cannot reincarnate to an animal, that it takes 49 days from your death to reincarnate to a human, because your souls are wondering around.