Spotting 4 days after plan b is this normal? if it is when can i take a pregnancy test after taking plan b?

Two weeks : A home pregnancy test can be positive two weeks after missed period. Calculate from there and do the test accordingly.

Plan B: Spotting certainly can occur after use of plan B. You can take a pregnancy test if you miss your period. Emergency contraception symptoms can include spotting or bleeding, changes in menstrual flow or your period may be late or early. Because plan B can alter menses, some women test for pregnancy if they have not seen it seven days after it was anticipated.