Could pills be the reason for delay of my period?

hi i had unprotected sex with my boyfriend 1 and half month earlier and he had given me pills after 32 hours and my period date was 1 november but period starts eariler at 15 oct . i tested my pregnancy it show negative after then i relax but till 16 nov i had missed period in between we had never sex

i want to know am i pregnant and reson for delay of period