What are these lumps on my inner bottom lip of my mouth?

Exam: Probable mucous retention cysts; however, without a photo, you must be checked by a certified dentist/oral surgeon.

Lumps on lip: Without a clinical examination, it is difficult to make a diagnosis. However, what you describe sounds like mucoceles, which are small mucous cysts. They are harmless and usually go away on their own. For a definitive diagnosis, see your dentist for an examination.