Hi I have this kind of dark red nearly black perfect round spot in the inside of my right cheek. It doesn't hurt in the slightest.. it's about 4mm in diameter and is no different in feel than the lining of my inner cheek. I smoke and I am hoping it is not early stages of mouth cancer but after viewing pictures on the web of oral cancer it looks completely different. I felt it today by chance with my tongue after eating a meal. I used my tongue to remove a bit of food from my back teeth and felt this lump... When I looked in the mirror I nearly fell through the floor. I couldn't believe my eyes what I was seeing in my mouth. I have had no sexual contact whatsoever for a long time.. 1 yr maybe, so it's not sexual I am positive. Please experts or anyone.. give me some advice :)

As you've probably read here already on the other thread on this topic, you have probably inadvertently bitten yourself. You can rinse with some warm salt water and if it hasn't gone away in the next week you can have your dentist take a look at it.
I find the same thing on many of my patients and most of them don't remember biting themselves but it is gone the next time they are in.
Don't worry about it unless it changes colour, size or texture.

For what it is worth, I would like to urge caution in simply dismissing your red spot on your inner mouth as merely a bite. It reminds me of a recent similar case I have seen at the ENT (Ear Nose Throat or Otolaryngology) office in which I work as a registered nurse. A patient came in and complained of virtually the same symptoms as yours. Our specialist at first came up with the same diagnosis as was posted here. It turns out the patient had been exposed orally to HSV-2, which is more commonly known as genital herpes. As this "bite" did not heal in an ordinary timeframe, we took him in for further testing and indeed he had contracted the virus. The sore eventually became further exacerbated by normal mouth activities (eating, brushing, rinsing with mouthwash) and developed into a full blown lesion. The downside to this is that it was an open lesion, approximately 2 inches in diameter and the patient had to be referred to a specialist dealing with infectious diseases. The patient, naturally, was extremely ill and eventually was admitted to the hospital as he could not have full function of his mouth while in break out. Not to get to crass or personal, but if you have had your mouth on the gential area(s) of anyone recently and are still experiencing symptoms, that you consult a physician immediately and ask to be tested for HSV-2, BV (Bacterial Vaginosis) and Gonorrhea. The final treatment this patient endured was a buccal mucosa grafts and malarplasty, which is extremely painful and disfiguring. Basically, this means he had to have the lesion removed by cutting out the affected cheek, if you can imagine the horror of such a procedure. Remember, people, the only safe sex is no sex and do not assume you cannot contract infections in your mouth you would normally find elsewhere. I wish you the best of luck and hope everything turns out for you.