I'm worried about my friend if she continues like this she will be pregnant or something bad will happen!?

Well my friend is 14. I would consider her to be one of my best friend's. When i first met her at the beginning of the year she was innocent and smart. Well then in January i actually remember the exact date it was the 21'st, she started smoking weed. She changed immediately. She began being slower in cl, hanging out with complete losers, and just making dumb choices. Well now it's March and she's now cut down on smoking weed but she drinks everyday. There is this guy named lets call him Sam well Sam has unlimited access to alcohol so today after school my friend lets call her Natasha well Natasha went to Sam's house also with this guy named Kyle and Kyle is a complete pot head and idiot. So around 7 i get a txt from Natasha saying that she made out with Kyle and Sam, she saw Kyle's k and she showed him her . Tomorrow she said she is going to Sam's house again and is going to make out with Kyle and have a good time i was invited and i could go make out with Sam but i said NO flat out. And i know Natasha and she will keep going and i am worried she will get pregnant or something bad will happen to her! Help i just want to get my friend some help before it's too late what do i do. PS Kyle's 14 and Sam is 16. Sorry about the bad grammar and if it makes no sense i am in a hurry!