Is it to soon to tell if i am pregnant its only been a week?

everyones giving me **** cause i hadn't had been on my birth control for a month and i didn't know i was going to be hooking up with one my new boyfriend we had 3 times with in 12 hours and even hes freaked out that i am going to get pregnant i am supposed to start here in a couple of days but i dont get my cramps like usual and i dont get all my pissy moods. i dont know what to do cause im only 17 and he just turned 18 but i am feeling kinda sick and my back is killing me so i dont know what to do and my mom kicked me out so i am living with a friend and can't get a blod pregnancy test cause i am to young what should i do i need to know i am freaking out badly