Ortho Tri-Cyclen (generic name: norgestimate/ ethynil estradiol) is a combination oral contraceptive. The recommended administration is as followed: an active tablet is taken consecutively for 21 days and then followed by an inactive tablet for 7 days. The intervals between the tablets should not exceed more than 24 hours.
If taken in this manner, withdrawal bleeding is expected to start within the 7 days you take the inactive tablets. As you can see, when exactly the menstrual period would begin cannot be determined for sure and minor variations (one day as you reported) are considered pathological.
However, you might want to visit your gynecologist to check if additional factors influence the start of your menstrual period.