Is it normal?

Pinky

So I've been taken the Plan b pill like every other month or 2-3 month apart. The last time I had my period wasn't like my normal periods. It was like almost 3weeks earlier than usual plus it's way lighter than normal. I just had my last period like two weeks ago and my current period just started. My normal cycle is about 28-31 days. So could this be because of me taken Plan b pill too often? Please help?!!!