I took plan B about 4 weeks ago and I got my period 5 days after taking it(5/26). I had just gotten off my period exactly a week before then(5/19). Ever since then I've had protected sex multiple times and was expected to start my period 6/7, and I never did. Now I am 14 days late. Within those 14 days I had light spotting that was dark brown for a couple of days, which was defiantly different from my normal heavy periods. Is this just a side affect to plan B or should I take a pregnancy test because of the late period/spotting?