Only 1 week on the pill... Hmmm

I have only been on the pill for 1 week as of yesterday... To tecnichally it's been 1 week and 1 day. My my boyfriend and I had unprotected sex today and he came inside of me... Oops. So I'm curious now what are the chances I will get pregnant? I personally wouldn't mind having a baby at this age however he does mind and would prefer not to yet. So now I am thinking a lot and I am getting more and more worried. I know it probably wasn't the best idea but it was heat of the moment and then oops... Please don't judge me.. I'm just looking for advise or percentages... Something to give me an idea of what I should expect. 
Thanks! ❤️