I say, tell 'em to shut the heck up!!
 
We had four extremely mellow, easy going babes, one right after the other...and then came #5...our "hell on wheels"!!
 
Although, we never actually made a decision to have another...it always just happened.
 
I say do what feels right for you. The age gaps between our kiddos is 5 1/2 years, 26 months, 21 months, and 2 1/2 years.
 
I've gotta say the 2 1/2 years was the easiest transition! Course, it was #4 to #5, so maybe we were just old pros at it by that point?!