Menstruation postponed 20 days with pregnancy test stick test did not pregnant the most

Menstruation delay 20 days, check not pregnant, may be caused by endocrine disorders, and often stay up late, sheriff pressure is too large, emotional excitement, lack of rest, spicy diet, etc. Secondly, there may be some gynecological inflammation caused, such as vaginitis, cervicitis, endometriosis, pelvic inflammatory disease, etc.