I just had unprotected sex and right after my lower abdomen started hurting and i felt nauseated. i can't move or cough. what is wrong?

Panic attack: You have nauseated yourself with your irresponsible behavior and had a reality check of all the issues your high risk behavior may cause. See your doctor about getting checked for herpes, hpv, all sexually transmitted diseases to include HIV and take the morning after pill to avoid pregnancy. Doing high risk things and then worrying about the consequences are anxiety producing.