Did I make Greek Yogurt correctly?

A home cook attempted to make Greek yogurt by heating milk, cooling it, adding a yogurt starter, and incubating it in a crockpot overnight. After 9 hours, the yogurt wasn't thick, but after 20 hours, it thickened enough to strain. Concerned about food safety, particularly due to pregnancy, the cook questioned whether the yogurt was safe to consume. The extended time at room temperature raises concerns about bacterial growth. While the yogurt's smell and appearance are positive signs, they don't guarantee safety. Pregnant women are particularly susceptible to foodborne illnesses, so caution is advised. The husband's willingness to try the yogurt offers a preliminary test. Ultimately, discarding the yogurt might be the safest course of action, despite the effort invested.