I'm 5 days late?! (used plan b)

A month ago on August 30th, the last day of my period, the condom broke when he came... so I took Plan B 2 hours later. 3 days after I spotted for 3 days, nothing heavy. 
​Does that mean that the pill worked? 
I've been stressed out about this this whole month till my period, and it didn't come on Sunday so I'm freaking out now. I'm testing on Saturday..!
​I know stress can definitely delay your period, but I can't help it.