Oral Contraceptive Pill (OCP) Pharmacogenomics

The goal of this clinical trial is to evaluate how differences in specific parts of our DNA can influence how individual bodies break down the hormones contained within oral contraceptive pills, which could affect how well these birth control pills work to prevent pregnancy. The investigators are also interested in exploring how these differences in our DNA can also explain why patients taking the exact same formulation of birth control pill will experience very different side effects. The main questions it aims to answer are:

* Do individuals with the CYP3A7\*1C variant have increased metabolism of both desogestrel and ethinyl estradiol when taking a combined oral contraceptive pill? * Do individuals with the CYP3A7\*1C variant experience higher rates of breakthrough ovulation while taking a desogestrel/ethinyl estradiol combined oral contraceptive pill? * What novel genetic loci are associated with alterations in steroid hormone pharmacokinetics and pharmacodynamics among a larger cohort of combined oral contraceptive pill users?

Participants will take a specific formulation of combined oral contraceptive pill (desogestrel/ethinyl estradiol) and undergo the following procedures:

* Blood draw to measure the amount of progestin and estrogen in their system from the combined oral contraceptive pill * Questionnaires to assess side effects possibly caused by the combined oral contraceptive pill * Blood draw to measure endogenous hormone levels and biomarkers that may be affected by the combined oral contraceptive pill * A transvaginal ultrasound to measure any ovarian follicles (optional procedure)