whoops

So 2 weeks ago I had sex and I took the plan b pill and then this past weekend I had sex. But now these past 2 days I've had weird mucus like discharge but it was brown and also kinda bloody and I thought it was because my period was about to start. But then like now today there wasn't really any discharge but I'm somewhat cramping. Any thoughts on if it's my body prepping for a period or is it something different?