I need answers

How long for it take for your stomach to stop hurting bc Thursday i try to have sex with this boy i been on and off with (first time) but it’s dick didnt go inside of me and since then my stomach been hurting like little craps what do that mean yes I’m on bc call nexplanon and how can i let the plan go away? I talk to my close friends about it they said it might be just sore but i do not want my family members to find out if i gotta go to the doctor 😩