You'd only know for sure, WHEN YOU SPARKLE!
If you are a vampire in the Twilight series, the above is correct.
It you are a vampire in the Buffy the Vampire Slayer series, you will know by the physical transformation of you face when the "Feed" is upon you.
Bram Stoker's vampires couldn't be seen in reflection (mirrors etc).
My best suggestion would be to check with the author or creator of your particular brand of fictional existence for all of the details.
if you haven't read the book i won't tell you. but someone puts vampire venom in her.
Are you positive that he/she's a vampire? If so tell him/her that you don't care that he/she is a vampire. Don't panic maybe they'll bite you and you'll become one too.
You become a vampire if you get bitten by another vampire
No, Charlie doesn't become a vampire.
Esme become a vampire in 1921.
You have to be bitten by a vampire to become a vampire
u can become a vampire on level 5 just go to the Darkovia Forest and go to the Vampire Castle and ask the Vampire Queen to become a Vampire
To become a vampire, have one bite you. Then drink its blood. The only researched way to become a vampire is to become bitten by one. However with vampires being fictional creatures (so far), this is unlikely to happen even if you were bitten by someone (This would most likely result in you requiring a rabies jab and no vampiric powers).
you cant become a vampire, grow up.
If another vampire bites you, you become a vampire
A vampire must bite you for you to become a vampire.
you go to the darkova wood's and enter the vampire queens castle and become a vampire