I might have a new way to get a pregnant girl’s contact info, I just need to find the pregnant girls in the wild. I imagine places like Walmart and grocery stores are an easy place, but is there anywhere else? How often do you find pregnant women in particular places, if you can remember?

A significant factor would probably be the overall fertility rate of the country or city you're in. If the women in general are barely having kids in your area, then you'll barely encounter any preggos at random.

I'm in the Philippines. A 3rd world country with a high fertility rate. Pregnant women are pretty much everywhere here. I've rubbed bellies at the gym, grocery, restaurants and randomly on the street... They would pretty much go anywhere non-pregnant women would go. Even bars and clubs would still have preggos once in a while. They wouldn't drink but they'd still hangout there.

There are no places I can think of that would often have pregnant women other than hospitals, fertility clinics, birthing centers and baby supplies stores.