Pregnant, Not Circus Freak

For the past couple of weeks, everywhere I go, I have noticed that strangers will just stare at me (and other pregnant women about to pop, I'm sure) like I am from another planet.
Yes, there are the kind, knowing smiles from many, but others just stare like they are either confused or disgusted or they think I'm about to lay down on the floor and birth this baby right there in the store.  (I'm not even going to get into the ones who huff and puff with impatience behind me because I walk so slowly)

Unable to keep my attitude in check at all times anymore, I have asked a few rude starers, "Can I help you?", to which they do not reply, but just keep right on staring.  And I just stare right on back like I am in the fifth grade.

I have been tempted to say, "Have you never seen a pregnant woman before? How do you think you got here? ****!"

I'm sure most of these people are not staring to be rude, and could very well just be concerned for the waddling shorty sporting a large watermelon around her midsection wondering how she's able to stand upright.
Either way, didn't their mama's teach them it's rude to stare?