If you haven’t used a hormonal birth control in the past month or have been using only condoms, a diaphragm, or other barrier method of birth control in the past month
Count the first day of your menstrual period as Day 1, and insert your first NuvaRing® into your vagina on or before Day 5 (but no later, even if you have not finished your period). During this first cycle, use an extra method of birth control, such as male condoms or spermicide, for the first 7 days of NuvaRing® use. If you insert NuvaRing® on Day 1, it is not necessary to use an extra method of birth control.
Here is what I found on the Nuvaring website.
If you haven’t used a hormonal birth control in the past month or have been using only condoms, a diaphragm, or other barrier method of birth control in the past month
Count the first day of your menstrual period as Day 1, and insert your first NuvaRing® into your vagina on or before Day 5 (but no later, even if you have not finished your period). During this first cycle, use an extra method of birth control, such as male condoms or spermicide, for the first 7 days of NuvaRing® use. If you insert NuvaRing® on Day 1, it is not necessary to use an extra method of birth control.