Maternal-Fetal Dr


So I’m going to an appointment today and I see the scheduled another for next week but it is with a Maternal-Fetal specialist... I had trouble getting pregnant and didn’t know until 5 months, but at the last regular appointment they said everything was fine this appointment being scheduled is news to me . Should I be worried ? Why wouldn’t my dr call me if something was wrong with us ? I’m trying to stay calm but now the time is dragging by and I can’t stop worrying about what I am walking into at this appointment. Has anyone ever seen a maternal-Fetal dr?