I started brown spotting a day before my period was due. 3 days now very light hpt neg. my normal period is heavy never like this why?

Light period.: The main reason for light periods is a change in hormone levels. Causes for what seems to be a light period can include: implantation bleeding in early pregnancy, thyroid problems, eating disorders, excessive exercise, initial periods for a girl, use of an intrauterine device, oral contraceptives & perimenopause. Can take home pregnancy test if uncertain if this is actual period. Take care.

Spotting & pregnant: If you have early spotting you may have a normal pregnancy. I like to get two hCG levels two days apart. If you are using vaginal progesterone, that causes bleeding in up to 50% of women. If you have spotting and pain on one side, you could have an ectopic pregnancy and must share this possibility with your physician.