RecruitingClinical trialSerum Biomarkers to Characterize the Effects of Therapy on Ovarian Reserve in Premenopausal Women With Early-stage Breast Cancer or BRCA MutationsThe purpose of this study is to learn more about the effects of your BRCA mutation on the ovaries. The BRCA gene can make it hard to conceive a child in the future. It may also bring on early menopause. The researchers will check blood levels of hormones that the ovaries produce. The hormones that researchers will check are anti-Mullerian hormone (AMH), estradiol and follicle stimulating hormone (FSH). The researchers will do this before, during, and after cancer treatment. The researchers will also ask you to fill out questionnaires about your menstrual cycle (your periods) and information about your health and pregnancies. This may help us learn which women will be more likely to have early menopause.