I have the nextplanon implant and my bf condom broke & we didn't know. he said he might have came inside of me a little. could i get pregnant?

Unlikely: Your chances of pregnancy using the Nexplanon and having unprotected sex are about 1 in 100 over the course of a year. So one instance likely won't get you pregnant. No contraception is 100% but Nexplanon is about 99%, so very close. If your worried, you can take a pregnancy test, but i'm guessing it will be normal. Hope that helps!