Hello, I Have A Complicated Situation. I Was On Birth

Hello, I have a complicated situation. I was on birth control for a couple years. I took a small break (1.5 - 2.5 weeks) and started them again. I was on the pills for 5 days before having sex. I know to use a backup, but the condom broke and he did not withdraw. I took plan b 6 hours later. I spotted for a couple days a week later. However, it has now been 3 weeks and I have yet to get a legitimate period. I have been taking my birth control at the same time every day, so my periods have never been regular. What are the chances of pregnancy?