Depo-Prover Infertility

i’ve been on the shot for the past 5 years i recently did not go for my last one on jan. 17th. i no longer wish to use this method of BC because i eventually want kids. i’ve had unprotected sex twice since i haven’t had the shot and am kind of worried i will get pregnant but because i’m afraid of being sterile i push the idea down. the sex was on the 28th & 29th. should i get the plan b? part of me wants to wait and see if i get pregnant then handle the situation.... can anyone offer some advice or constructive criticism???