Had unprotected sex a few weeks back. my period is due the 12th and i am spotting just light and little blood? what can this be?

Your period : If your period is due and now you are spotting then that is likely your period. Home pregnancy tests are very accurate. They are the same tests used in a doctors office. They can detect a pregnancy 7-10 days after conception. The best time to take one is when you miss your period. If you doubt the result you can repeat it in 1-2 days.