I had unprotected sex about a week ago and i'm exhibiting signs of pregnancy. i feel as though i might be. is this possible?

Yes: Unprotected sex can always lead to pregnancy. If you've missed your period, take a home pregnancy test as they are very reliable and accurate ways to determine if you might be pregnant. At 16, if you're not pregnant, a reliable form of birth control would be a great idea. Pills and condoms provide pregnant protection and protection from stds, which are definitely out there good luck.