For a long time in this country the family size was 2.3 kids (2 kids and a dog). Now times have changed and so have the sizes of the family but many have not changed the mindset so you have the nay sayers.
You say you have many friends without children well that is one thing that is going to have to change because they do not understand what you go through to bring up baby and siblings. One day they might but you will still be in another phase of your life and not be in contact with each other. So do the mommy day out thing to meet other moms in the same boat.
Other people wonder how you can financially afford to care for your children and provide the "required" college for each at the present and increasing tune of $150,000 per child. This does not include your present everyday cost of clothing, food, shelter, medical, sports and activities.
I say this from the older person view but I am not downing or dogging your or anyother mommas on here that have more then 3. I had two and wanted a third but moving around in the military 25 years ago was not conducive to having more than 2 and having a nice place to live when you got orders here in the states or outside the states and pets made it worse when moving or traveling.
So for the record, hold your head up high. Oh when someone really does open the door let them as they feel they are doing something good for mankind even if you can do it yourself. Also grow a tougher layer of skin so that everything that is said does not sink in and become a negative.
Have a good season and a good new year.
The other S.
PS You could also make a time just for me time and go out for a lunch or dinner with the girls without the kids. This will make you feel more like an adult and able to cope and appreciate your kids better.