I'am 18 with a birth injury my mom said. So can I go after compensation?

Ask a lawyer. This is a legal question best answered by an attorney familiar with the laws in your state, regarding this matter.
Not in my state. In Texas.the parents have until the kid is eight years old to file any cause of action on a supposed birth injury issue. You don't get a second run at this issue when you are 18. In some states where the legislatures favor trial lawyers, the rules are more lax.Seek a local attorney to see where you stand.