My bf and I had unprotected sex, and I am so scared I might be pregnant..?

And to you Busy....you are not pregnant, so don't worry.....but i must say ... Last night my boyfriend and I had unprotected sex. He ejaculated twice. ... Am I pregnant? I'm due to have my period on April 20th. Could I be pregnant? ..... im 16 im scared the last time i had my period was i believe the end of may i ...