Plan b- Did it fail for you? Advice?

Okay so husband and I had unprotected sex the 4th, the condom broke so I started to panic, i knew my ovulation was near (according to this app) but i took an ovulation test to see, and of course two solid dark lines. So I knew I’d be ovulating in the next 12-36 hours. 9 hours later (Jan 5) in the morning I took Plan B but I’m worried. The box says it delays ovulation, but I read online that once you have a confirmed LH surge it does nothing, even if you aren’t due to ovulate for at least 12-36 hours. Do you guys think it’ll work for me?

One weird symptom I just got was heartburn. Maybe it’s food related or idk, but I’ve NEVER had heartburn other than when I was pregnant with my first, and even that was later in my pregnancy, but this heartburn has been severe, it’s been ongoing since last night and nothing is helping.