13 years old pregnancy....NEED HELP NOW PLEASE!!!?

2 days ago,I had sexual intercourse for the first time. We didn't wear protection and yes, he cummed. I just got my period the day after, but I'm wondering if there's still a possibility that I can get pregnant. I just checked my pad, and it's, like, flashy red. I don't know what's going on!! Help?? Please? Should i take the "next morning" pill, or am I okay??? Or something? Erm... I DON'T KNOW WHAT TO DO!! People say that if a have my periods I have more chance of beeing pregnant ...! PS:my parents can never know. ANY HELP !!??? (its been 3 days)