took plan b

Howdy girls!
So, I had sex on Friday and I took plan B about 13-14 hours after sex. It wasn't my first time, so I didn't bleed any during sex, and I know not everyone does. 
My question is, I took the pill and that day I was tired and I am continuing to feel tired. I haven't had any spotting or anything. Some diarrhea but that's all. 
Is that normal? My period is due in 3 days, I'm fairly irregular, and I know that taking the pill can throw off your cycle. 
I just want to make sure this is normal, and I just need to wait it out?
Thanks girlies!