Ugh... I give up after a while on these. Opinions are fine and totally valid.
But people throwing about random facts with no sources to back those facts up? Anyone dizzy yet from going round in circles? 
And many countries think a child needs to stop breastfeeding once the mother is pregnant again
Fortunately for you, researchers have looked into this, and found no such effect
(NOTE: two quotes from both sides of the argument, both need sources if we're going to be making statements instead of expressing opinions)