Three Days Before My Period Last Month I Took A

Three days before my period last month I took a Plan B emergency contraceptive pill due to a condom breaking. I've been on birth control for a few years and I am pretty consistent with taking it every day although not always at the same time. Due to taking the Plan B emergency contraceptive pill only a few days before my period is supposed to start I receive my period and It was normal. However now it is a week and a half before my next period, And I Have spotting that is close to the flow of the beginning days of my period. Additionally I have been extra tired with severe headaches for the last few days which I don't normally
Get from my period. are these normal side effects from taking plan b? Also, is it normal that I'm having them a month later?