What should you do if you were 16 and started dating a guy who was 18 and you got pregnant then found out he was married and you haven't seen him since and now your son is four months old?

You didn't mention if you knew he was married when you went into the relationship. However, it doesn't much matter, but it would be wise for you to make him pay some child support to help you out and you can also go for total custody if you so choose. This doesn't mean you will get total custody if the father of the child fights the issue which is highly doubtful.
You didn't mention if you knew he was married when you went into the relationship. However, it doesn't much matter, but it would be wise for you to make him pay some child support to help you out and you can also go for total custody if you so choose. This doesn't mean you will get total custody if the father of the child fights the issue which is highly doubtful.