oral contraceptive pill, oral contraceptive, progestogen, contraceptive pill, clomiphene, isotretinoin, norethindrone, spermicides, tamoxifen, nifedipine, hormone replacement therapy, secondary amenorrhea, contraception, oophorectomy, hyperemesis, norethindrone acetate, clomiphene citrate, progestin, spironolactone, estriol, estradiol, oestradiol, anovulation, epidural anesthesia, mifepristone, amenorrhoea, medroxyprogesterone, antidepressants, contraceptives, estrogen, progesterone, magnesium sulfate, endometrial carcinoma, anticonvulsants, hydroxychloroquine, pessary, metformin, hysterectomy, stress incontinence, tricyclic antidepressant, caesarean delivery, antiepileptic drug, alendronate, statin, postmenopausal, ergotamine, endometrial cancer, cefuroxime, hypnotics, premenstrual syndrome, menopause, nelfinavir, nsaids, emend, premenopausal, clomipramine, celecoxib, venous thrombosis, endometriosis, glyburide, iud, indomethacin, leflunomide, cryptorchidism, diethylstilbestrol, menstruate, acetylsalicylic acid, tranylcypromine, luteal phase, hrt, menses, luteal, pravastatin, oestrogen, anal intercourse, intrauterine device, thyroxin, amenorrhea, folic acid, zidovudine, black cohosh, pimozide, poliovirus vaccine, aspirin, haemorrhagic stroke, varicocele, dapsone, dysmenorrhea, ddi, valproic acid, hyperemesis gravidarum, ethosuximide, phenytoin, flecainide, tubal pregnancy, abruption, indinavir, intercourse, pap test, thyroxine, pcr, ketorolac