By using birth control pills women can with quite good results reduce the amount of spots/acne on their skin. One thing the birth control pills do other than making sure you’re not getting pregnant is keeping your hormone levels steady. And you won’t have that typical increase in androgens which can cause acne.
The reason many women experience acne for the first time in their adults is because the hormone increase when getting their mentrsuation maybe wasn’t enough for them to set of an acne reaction. But when they got pregnant or went trough menopause it did. This is called adult-onset acne, or “acne when you’re adult” if you like. There are many different kinds of treatment for hormonal acne and I sugest you consult your doctor before starting any treatment.