Condom broke but used Plan B?!

Happened on the 30th of August, which was the last day of my period. It broke when he came and a bit went inside of me, and 2 hours later I immediately took Plan B. Three days after I spotted for 3 days (does that mean it worked?)... and today I was suppose to get my period but I haven't. is it just late because of the pill? I'm going to test soon. please help, thank you!