abnormal period

in june i had my period towards the end of the month and it went away with no problems. i just had a few cramps here and there with no issue. after my period went away, i had sex and took a plan b right away afterwards to make sure i wouldn’t get pregnant but now in august, everything was fine but I think maybe the plan b made my period come early or something. i got light bleeding, kind of like the very beginning of the period with no cramps just bloating. the spotting/period sometimes got heavier but not as heavy as it usually is. it’s been five days and it’s getting lighter. i just want to know what you guys think it may be. also the color of it is bright red and dark i wake up. i assume the colors have to do with the freshness of the blood. please let me know what you think!