Lost it

Alright so I lost my virginity on this past Saturday. I am just so worried that I am now pregnant. We started out using a condom but he took it off because he didn't like the feel of the condom. So we finished and he pulled out. I'm positive he pulled out soon enough but I am just so scared so I took plan b. Was that wrong of me to take Plan B? I really just need some help. I am a 16 year old girl I cannot have a child at this age. Please help!