Expired nexplanon/b.c. Plan b Questions

So my nexplanon has been expired now. Way over, been in since 12/2013 shame on me. It was free with my health insurance at the time after my daughter’s birth. I’m barely going to get health insurance bc I’ve been at my job and qualify now. I’ve been practicing sex with my partner of course but questions are: many free/low cost birth control sites out there. Could I take one of those and would they counter act each other and I get pregnant? Would plan b with an expired nexplanon be affective?