Plan B on period

I had unprotected sex with no ejaculation on my 6th and last day of period which was two days ago, my cycle is 31 days long and I ovulate on CD 17-18. I took the plan B yesterday for my own safety because although pregnancy chances weren’t high, I didn’t want to risk it. I’m still spotting from my period, but now I have a brownish spotting. It can be from the plan B hormones right? I’m really bloated too, but I didn’t throw up or had nausea