You are
definitely at risk for being pregnant, assuming that you didn't use any other form of birth control. The pill takes
at least 7 days to take full effect and for some women, it takes almost 4 weeks until their body is completely adjusted.
It sounds like you were hoping the pill could start working right away, like the emergency contraceptive pill. But it doesn't. Your body needs to time regulate itself so that it can protect you against pregnancy.
I would say the next best thing for you to do is to take a pregnancy test.