Taking tips and cues about future events that may or may not happen, is not a wrong thing or an illegal act.
You first decide if you want to go ahead with the proposed marriage or going snap the ties with him permanently.
Since you have a baby (or perhaps you are yet to deliver), it would be better that you bury the differences and try to live with him in marital relationship at least for the sake of yor child.
Consulting a lawyer about the future legal issues is not a crime neither you are restricted from consulting a lawyer for proper knowledge about your legal rights post marriage, it is your life hence taking precautionary measures is your right.