If my period was a week late could it still be possible that i'm pregnant?

Having a Period: Viable pregnancy stops vaginal bleeding. Having a period is physical proof that you are not or are no longer pregnant. If you have any doubts, please get a pregnancy test.

Don’t guess.: Take a test.  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. If you were pregnant the hormone level would rise enough for detection.