I have 2lumps in my mouth1 in my cheek which is visible1 in my tongue only can be noticed by pinching my tongue im 16 would cancer be rarest diagnosis?

Very rare: Oral cancer in a 16 year old who is not a heavy smoker would be extremely rare. There are many minor things that can cause lumps in the mouth, including trauma from biting your tongue and/or cheek. I would make an appointment with your dentist so that they can diagnose what is really going on and put your mind at ease.

Mouth lumps: At your age, cancer is highly unlikely, but it isn't impossible. There are a number of non-cancerous lumps or growths that can occur on the tongue and on the mouth. Best to have it checked by an ENT specialist. This way you'll know what your are dealing with and get appropriate treatment.

Yes, least likely: Oral cancer in a 16 year old is relatively rare, perhaps 1:500, 000 or more. There are lots of benign growths and other types of lesions that are much more likely. I suggest that you have it looked at as soon as possible to get a proper and accurate diagnosis and put your mind at ease. See an oral surgeon (or ENT specialist).