Did you pop the pimple or squeeze it? How long did it look like a pimple before it looked crusty that way?
How long ago was your last possible exposure for hsv1 (when was the last time you kissed anyone)? If it's been more than 4 months, your tests are conclusive.
The sore isn't ON the lips, so it's less likely to be a cold sore, though it doesn't have to be directly on the lips - it's just the most common. If it started out looking like a pimple, and you squeezed or popped it before it looked like that, it's probably a pimple that is now infected. You can try some neosporin (if you aren't allergic to it or any of the ingredients).