hello took plan b on July 9th

I've already got my period on Monday the 17th. it lasted for usual amount of time (5 days). I spotted a little yesterday. I'm still spotting a little more today (which I know is normal, per my doctor) but my mood has been very erratic. One minute I'm happy & the next, I'm anxious, sad & crying my eyes out. I've only taken the plan b once before & it didn't make me feel like this. I realize that this is only temporary but I feel pretty awful