Broken condom


Okay I got a nexplanon inserted last Friday so it's been a week and a day and my doctor told me it'd take 3-4 days to start working, but on some websites it says it could take up to a month so I'm worried. My boyfriend and I were having sex tonight and the condom broke, but he pulled out and I do have the implant. Do you think I'm fine or should I go get a Plan B to be extra safe? He says he's not worried, but I am sort of but at the same time I don't think anything is wrong. Helpp