re: I just found out I have 3 year old son

Yeah this sounds really fricked up. If she spent 3 years letting that little boy call him Daddy just to rip his whole world apart it's because something else happened. Not only did she divorce the only father her kid knew, now she's told him "Guess what, he wasn't even your father anyway, this complete stranger is." That's fricking cruel. Either her ex successfully petitioned the court to exclude him from child support or she decided you would give her more money than him. She didn't do it just to make sure YOU had a chance to know your son. She did NOT do this out of the goodness of her heart.