I've been taken pregnancy test here at home and it's negative. what happen? my period is n0t yet come.

Some possibilities: In a woman with regular periods, some causes of a late period include: excessive weight loss or weight gain, increased exercising, emotional stress, having an illness, traveling, medicines (like birth control pills), hormonal imbalances, etc… Seeing a doctor is a good idea if symptoms are persistent, recurring, or worrisome. Pregnancy is the common cause of a missed period, if sexually active.

Patience is Virtual: Apparently your body and that pregnancy test don't get along.So, maybe if you take the test every few days for the next week or two, they'll get to know each other. And by then you'll either have had your period or the test will be positive (or both, actually; we'll have to see...).Also, are your periods regular or not? If not, then you may have to wait a while; again, we'll have to see...patience