I'm 6 days late on period. negative test. i am always on time every month. i did have sex with my bf a week b4 my period was suppose to come. help?

Some thoughts...: Pregnancy is the most common cause of a missed period. If not pregnant, other causes of a late or missed period include: excessive weight loss or weight gain, increased exercising, emotional stress, having an illness, traveling, medicines (especially hormone pills, birth control pills), hormonal disorders, etc… A visit to a Ob-Gyn doctor is a good idea if symptoms are persistent or worrisome.