I was at the dentist said i might have a cold sore, i doubt it i have a pimple like bump no head it hurts when i bit it in my lip but that's it ideas?

Sounds like trauma.: Given your age it would be incredibly unlikely (but not impossible) that this lesion represents anything other than a benign lesion such as a cold sore or just a traumatic injury (did you bite or burn your lip?) i would keep the area clean and avoid continually injuring it. If it remains for 2-3 more weeks you should see you primary doc to set you up for evaluation and/or possible biopsy.

Bump: There are many possibilities and merely giving you a list of them is not really helpful. Almost all will be gone within a couple of weeks and nothing to be concerned about. If it's important for you to know what it is, see an Oral Surgeon for a more likely definitive diagnosis. In almost all cases we can diagnose these lesions just by observation. A few require a biopsy. Usually gone anyway!