I'm not sure if you know this already or not but some of the Stylist Sim custom clothing can be worn by pregnant sims. Just make sure they're wearing it just before they start to show.
If you don't already have the outfits, download the free ones at Stylist Sims and the donation ones here.
If you don't already have the outfits, download the free ones at Stylist Sims and the donation ones here.
