Is it wierd for me to want to get pregnant at 20 years old?

I don't think that I am going to act on it now but sometimes I just really want to have a baby. Me and my fiance have been together for 2 years and just got engaged, we haven't set a date or anything yet. When I see pregnant people and babies I just want one. Is this my maternal instinct coming out or is something mentally wrong with me?