Ask you doc... Ovcon-35 contains 21 pills of Norethindrone and ethinyl estradiol. This combinationhas been used in a long list of pills for many years. The "35" refers to the estrogen dose. Higher and lower estrogen doses are available. Noethindrone is an "older" progesterone. Newer pills contain different types of progesterone and each has pros and cons. Pills with 24 active instead of 21 are available.