Not sure if period is normal?

I took plan B back in November and my period came normally for that month. It lasted 2 days longer but wasn't as heavy as normal. This month my period was late 3 days and was relevant for 3 days and the flow wasn't as heavy either. When I took plan B back in November I did throw up within the first two hours but not a lot. Now I've been feeling tired and nauseous all the time. Are these normal side effects after taking plan B? I haven't taken it before.