title: Low-dose progestagens and ectopic pregnancy.
mesh_terms: D000328:Adult; D003276:Contraceptives, Oral / Q000009:adverse effects; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D009640:Norethindrone / Q000008:administration & dosage* / Q000009:adverse effects; D011247:Pregnancy; D011274:Pregnancy, Tubal / Q000175:diagnosis*; D013997:Time Factors
chemical_list: D003276:Contraceptives, Oral; D009640:Norethindrone