The primary objective of this trial is to examine whether ovulation is suppressed after use of hormone patches containing different dosages of ethinyl estradiol (EE) and gestodene (GSD) for 3 treatment cycles. To this end, the blood levels of endogenous hormones (hormones produced by your body) will be measured and transvaginal ultrasound examinations will be conducted at regular intervals. In addition, the concentrations of the administered hormones EE and GSD in blood will be determined in regular intervals.