Mom/Pregnancy Shaming

Sitting in the waiting room waiting for my appointment, and I'm wearing a Sea-Band, because for the love of God, with my nausea I'm desperate to try anything. And I immediately get slammed by a woman who is maybe 2-3 weeks further along than I saying that "only people who can't handle it wear them," and "if you can't handle nausea you can't handle motherhood." It didn't really bother me, but it definitely bothered some moms around me. Now they're having a heated debate about shaming. Good for them. 
Why do we have to compare one pregnancy or mommy to another?