I really don't understand why anyone would have a child because they thought they 'should' for some reason. You have a child because you want one - that seems like the best reason to me, anyway.
totally agree!

I am an only child and have never felt sad or upset about it...it was what i knew and to me it was perfectly normal and awesome regardless

(BTW after DD1 was born i had a PTSD from birth trauma and totally never felt like having more children...but have to admit that around 18 months i got the clucky bug ). In a way I am envious of your position and its surety. For me, I just am not sure that I will ever feel 'finished'...but really do feel that we should stop now....argh, either way...whether you want more or only one it is a battle field of emotion and conflict to get to that point.