Could Delayed Period Indicate Sign Of Pregnancy?

hi good evening..im carol, i just want to ask because its my third day now without menstruation. my last period is April 24, but l have irregular day period. Last March i had my period on the 11th. Is it possible that I am pregnant since until now i dont have my period or my period is just delay. please advise. and when should i have my pregnancy test? thank you