I just read about it at Sex in the Public Square. I haven’t thought about it before, but what she says makes sense. If you’re a sexually active adult who could technically conceive, but you don’t want to have a child right now, it’s a good thing to keep on hand.
I’d be interested in hearing about your experiences in buying it OTC, if you do so. It isn’t an issue for us, so we don’t have a reason to buy any.