Not all women post photos during pregnancy.
Some people do not publish them because they want them to remain a secret. And someone does not publish because of certain superstitions (this is normal for Ukrainians).
As an example of this, I can show the Instagram of the singer from the Ukrainian band Onuka. The video on May 5, as well as photos on May 8, which do not show that she is pregnant. And already on May 14, the message where her stomach is visible was published, and also the information that in their family appeared a kid.

And now about the most pregnant woman from Mariupol. If you did a little more careful investigation, you can find her husband's account in the marked Instagram photos, where there are photos of pregnant Maria 6 weeks ago. Here - https://www.instagram.com/p/CZHSs4lqMxE/

After that, there are still doubts?