Hi I just noticed two black spot inside of cheek - mouth on top of my left bottom teeth I have the two sport up and down close. Haven't bite it?

Black spots. I'm glad you recognize that black spots are not normal. Best option, make an appointment with your dentist or an Oral Surgeon for an examination. Second best option, give spots two weeks to completely disappear on their own. If still present after 24 days, get to a Dentist or Oral Surgeon immediately..
Watch for a few week. Watch for another few weeks-if it gets bigger or more appear would recommend seeing a dentist to make sure it isn't anything deeper. If you are a smoker or have been this is especially important.
Most likely yes. Most likely yes you have bitten it at some time and the black spot is just healed (coagulated blood) underneath the skin area. No worries, this will go away. Connect with my Virtual Practice on Healthtap for any dental questions with my special keycode: DFWMCQ! Securely video or text chat by virtual appointment. http://htap.us/28qexs.