If I understand your message correctly, you have developed swelling of your upper lip; not that you are simply dissatisfied with the size of your lip.
Most lip swelling is the result of an allergic reaction to a cosmetic or other substance applied to the lips, to infection (commonly with the Herpes Simplex virus) or to an insect or animal sting or bite and rarely secondary to excessive exposure to sunlight. First, give strong consideration to the substances with which your lip may have been in contact. However, lip swelling can develop as part of a condition called angioneurotic edema that is an allergic response to an ingested medication and this type of swelling will subside with discontinuation of the medication.
Almost all lip swelling, whatever the cause will spontaneously resolve with the avoidance of the irritant/allergen. There are a few, relatively rare causes of swelling that will not spontaneously resolve, if left untreated and these may requirement specific treatment with prescription medication given with directions by your doctor.
Good luck