L.B.
One of my friends has 4 children. They had to do fertility treatments to conceive the first one, the rest came "naturally". She had a C-section each time.
Of the 4, the oldest two are on the spectrum, the third is in speech therapy, and the 4th is too young to be diagnosed with anything (yet).
Their home is filled with laughter and love and each child thrives in his/her own way.
They have times they have felt overwhelmed, but, ultimately, they would not trade their lives for anything in the world.
Their children are special and wonderfully unique - as are their parents.
You don't need to explain anything to anybody. You will cope through the pregnancy because it is what we do. We, you, everyone, has untapped abilities that surface when they are needed. You are stronger than you think - so is your husband - so are your children.
Consider this child to be a blessing - with that low of a conception rate - I really think this pregnancy was meant to be. :)
Many hugs to you and yours.