Hi, My Gum At The Very Back On The Bottom

hi, my gum at the very back on the bottom right side is hurting and i find it difficult to eat and chew properly. It has hurt before and i thought it might be my wisdom tooth coming in because i saw a small cut and what could possibly be a tiny piece of tooth underneath. after a few days it stopped hurting so i ignored it. but now its back and i pushed the part where it hurt and some pus came out from the small cut and in between my gum and back molar. should i leave it to heal by itself or see a doctor? is it my wisdom tooth coming out? bcs i dont have any yet and im 20