I agree with babyonboardxox. You don't sound like you should be having sex if you don't know how pregnancy works. You should look into taking a sexual education class or reading some books on sex and pregnancy.
I dont mean to sound rude, but if you dont know how pregnancy works, you should not be having sex.
Use condoms and go on birthcontrol if you do not plan on becoming pregnant.
It only takes one sperm cell to get to the egg.
If you are not planning on having a baby there is a pill called plan b. Take this pill within 72 hours.
If he didn't ejaculate inside you it is highly unlikely you will get pregnant
We had sex in the afternoon