I have been spotting brownish pinkish for about 4 days. My period is usually the first week of each month. What is the cause of spotting?

Spotting can be an early sign of pregnancy.. take a test to know for sure.

How old are you? Have you had sex recently?

Sometimes spotting can be normal for you. I spot often.

Also, the brownish color may not be a period spotting, it could be discharge. Which is normal.

Do you have regular periods? Do you get your period EVERY 28-32 days, like clock work?

Some women have irregular periods. Which includes being late, missing a period, or spotting.

I was also a frequent spotter before my pregnancy.

Commonly, spotting can be caused by a B12 deficiency, progesterone deficiency, or early pregnancy.

Its very very common, so feel free to check with your doctor -- he/she can give you a good answer as it pertains to you--everyone is different.