How long for normal cycle after plan B?

Jewel
Hi ladies, so I know it's normal for plan B to mess up your cycles but I'm wondering how many periods you had until you guys started having normal cycles again?
I had sex on 3/11 but the condom broke so I took Ella 2hrs later; I was due to get my period the next day, felt all the pms symptoms) but because of Ella I got it a week later on 3/18.  
eve predicted my next cycle would start 4/15 but so far no dice. Just trying to be patient and not stress lol but I hate this uncertainty.