hi welcome to hcm.see first thing to know
pregnancy is missing periods as u have
irregular periods so it will be difficult to say but u have to urine pregnancy test and if it positive then ur pregnant and if not then no need to worry.see first thing u have to avoid unprotected sex because its may end in other disease like
syphilis,gonorrrohea,
HIV,hbsag etc.no the belief of your teacher is not true so not be confused just do pregnancy test and contact gyna for that.
thanks
dr.dhara
dhara.shah84@yahoo.in