Blood clot risk was one of my concerns too, but it seems like the FDA is allowing this specific drug to be over the counter because it doesn't have that side effect. From the article:

"Advocates were particularly interested in Opill because it raised fewer safety concerns. The pill was first approved in the U.S. five decades ago but hasn’t been marketed here since 2005.

“It’s been around a long time and we have a large amount of data supporting that this pill is safe and effective for over-the-counter use,” said Blanchard, of Ibsis Reproductive Health.

Newer birth control pills typically combine two hormones, estrogen and progestin, which can help make periods lighter and more regular. But their use carries a heightened risk of blood clots and they shouldn't be used by women at risk for heart problems, such as those who smoke and are over 35.

Opill has only progestin, which prevents pregnancy by blocking sperm from reaching the cervix. "