I'm the oldest of 6. Which mean my parents had 6 kids together. It wasn't a blended family.
When I miscarried a baby between #2 and #3 my mom said "Well, good, now you can concentrate on other things." and my dad said "Well, that what they make condoms for."
I was devestated at my loss and they blew it off as a "good thing" for me. My one sister had had repeated miscarriages and was still trying for that first full term pregnancy. They never told her those things.
I felt like I was slapped in the face after my loss. It was horrible and it just made me realise they didn't matter. My family was MY family. Their family was THEIR family.
We did have baby #3 and the comments were not pretty. Then we had baby #4 and they got just as bad and just as rude. We didn't listen and we didn't care. We knew we wanted a large family and that is what we were creating and SUPPORTING! It just pissed me off that my parents who had 6 kids of their own were upset and MAD at me having just as large of a family! It seemed so hypocritical of them!
My dad frequently questioned my ability to look after and take care of "all those kids" and it got worse when we chose to homeschool instead of public school too. Suddenly I was truly insane for birthing at home, having a large family, and now home schooling.
At one point I just went off on my dad in an e-mail telling him how it was our family and not his. That he could accept it or just not visit anymore, as we didn't need the negativity. We struggled a little financially but not to the point of asking for money from them. We made it through and we're still making it through.
With our 5th we got dulled congratulations, but no more disappointing comments. That was later when I was well into the pregnancy that's when my dad would say really stupid and ignorant things like "Do you know what causes that?" and otehr idiotic things.
With our 6th we just didn't tell anyone again. We kept quite as long as possible to family. Or so we thought, LOL. Apparently friends of friends told my parents so they knew they just never said anything to us. My dad said that if we wanted them to know we would have told them. Which is true, but oh well.
Still my dad asked the stupid question which we had already given smart alleck answers to the pregnancy before. We just gave new smart alleck anwers to again. If they said "so are you done yet? We'd say - "We don't know we'll see."
It just floors me too. I have the most children and my large brood is so much more well behaved and more polite than my sister's kids. They each have 4 each and are more hyper and hard to control than mine. Even my objecting father has said he would much rather take my 6 out to eat in a restaurant than my sister's 2 at the time, because mine will sit and actually behave where as my sister's kids bounce off the walls! Ironically my sister's kids aren't allowed sugar, LOL, and my sister is a control freak. I'm a laid back mama, which is why I think my kids are more relaxed.
I have found in my family that once I hit baby #7 they throw the towel in and start pushing ans asking when the next baby is going to come, LOL.
So now we find ourselves on the opposite end of the spectrum. Before it was disgust and discouragement at the idea of notion of us having "another one". And now it's, anticipation and encouragement to having another one! Even my MIL asked us at 6mo PP if we were pregnant again yet! LOL Only because it seemed to be our M.O. to be pregnant again about 6 months after a new baby arrived.
Now we are on #8 and still the same dull congrats, but no more negative comments. It just sucks that we had to put up with all the BS from family the way we did.
People, even family, don't always realize how insensitive and hurtful they are being. I am sorry your family is just as rude as mine, if not worse. You aren't alone and just know that if you plan to have more, it doesn't involve your family and you have every right to keep the negative away from your family.
{{{HUGS}}}
I hate that anyone is going through anything like this, too. 
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I am a wee bit afraid that they will react like your family did
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