Need help please!!!

Sofiya
I start using this app about a week now so i am new i dont know much about it.I Had my period on the 23 to the 27 of August and my period supposed to start on the 19th of September, i had sex on that same day (19th) and up to now there is no sign of my period coming. My partner didn't cum inside me. Could i be pregnant?? Please help. Thank you.