good afternoon thnxs for your Question. dont be so panic.  i think u should consult gynecologist so that proper history and examination help in diagnonsis. but if her tentative date of period is 4th oct. and u did sex with her on 2nd oct. than immediatley i pills given,  that mean u did sex in non risky days so less chance of pregnanacy . her period might be long beacause of i pills. but make sure with gynecologist .