(May 19, 2018, 7:19 pm)doubleintegral(May 18, 2018, 11:39 pm)1Way You can't by just looking at her or checking if she has a ring or not. The only non sleezy way is to just go up to her and ask.
The vast majority of single pregnant women will not be wearing a ring. but they are hardly common.
You must not get out that much if you honestly think that. I get that you're a random internet asshole, but don't have a piss-fit when you're proven wrong.