Texas allows for a form of common law marriage.
But technically to be so married is the same as any other form of marriage and would take you off the parents medical coverage. Or to consume benefits after you were married might be view as a form of fraud .
Now I'm a bit old fashioned on some topics--but unless your proposed husband adds a good medical coverage plan to the union I might hesitate about a formal union of any sort any too soon. .
Aside, under the quirky financial aid rules of FAFSA your need based aid may well go up once you have a live child.and your parents ability to pay drops out of the equation.