I addition to everything that anxious207 mentioned, please learn something from this experience. There is a reason why we should respect minimum age limit to consume alcohol.
O.k. There are a few things you can do to help you ease your fears. First, Did you feel like you had sex the morning after? Was there any stuff in your underwear?, Next, talk to your friends and ask them to tell you everything they know about the night, Can you talk to him possibly and just tell him that you need to know what happened? If he has your number and calls or if you can get his number from a friend. Just say "sorry to call but I really need to talk to you." Even if your embarassed about calling, DO it anyway, you will feeel better after and its for your safety! You can also take a blood pregnancy test at a doctor's office 10 days after the incident. A urine test 14 days after. Also, do you know when your last period was? Women usually can only get pregnant during a certain amount of days after the first day of your last period. IF you find out that you are pregnant, there is a pill you can get from an abortion clinic that when taken, causes you to bleed everything out. Its like having a heavy period. If you look online "Pill that causes miscarriage" it will give you the name of the pill. This pill can be taken up to your 9th week of pregnancy. No surgery, nothing. Just like having a heavy period. You may also want to get tested for STDs if you find out you did have sex. Its important to get to the bottom of what happened that night. Be proactive. You can do it. I wish you luck and hope that everything works out!
Consult your gynecologist