Any other symptoms besides the fact that there's a lump? Does it change in size, does it bleed, is it really firm and hard or is it more "squishy?" It would be best to either see a dentist or your primary care physician to get it checked out.
Its squishy and it changes size everyday
It may be a blocked salivary gland. You should get it checked out by your primary care physician. Or your dentist can make a referral as well