I’m adopted and I have my original BC.
You might very well have your original, I’m sure.
The question might lie in which state you’re in (they have their own rules) and if you have the original BEFORE they changed the records post-adoption.
IOW, see what you get if you head to the office and ask for your birth certificate NOW. They may not be the same.
Hence, the rub.
Several freepers have mentioned that different states have different laws about this --- and apparently there's even an article at eHow.com on how to get your original BC if you were born in Texas and later adopted.