How accurate is a pregnancy test if it is taken a week after your period ended? I took a pregnany test and so far it's saying that I am not pregnant

I will assume this is tied to your other question.

You had sex right before your period, and had a period, now a week latter want to take a test.

It would not be effective at all, you will have to wait till the next period date for it to really show.

While the odds are no you will not be, you have about another month to do before you can be sure.