scared

hi guys. i just joined this app. but i'm scared because i am 16 years old and my period is late. i had sex a little over a month ago. we used a condom. but he didn't pull out. i had a period the following week but i was told if the egg got fertilized it would affect my next period so i wasn't in the clear. my parents don't know i'm sexually active. i'm terrified of being pregnant and i don't know how to handle this. i don't want a baby. what should i do?