Short Answer:
No.

Long Answer:
Canker sores are not a form of herpes, however, they are often confused and mistaken for cold sores.
Canker sores, also called aphthous ulcers, are small, shallow lesions that develop on the soft tissues in your mouth — under your tongue, inside your cheeks or lips, and at the base of your gums. Unlike cold sores, canker sores don’t occur on the surface of your lips and aren’t contagious. They can be very painful, however, and can make eating and talking difficult. Canker sores, especially of the lip or oral mucosa and can be caused by acute stress, trauma to the area in your mouth, allergies, or by a reaction to a particular bacteria.

Short Answer:
After you are infected with HSV, the virus remains in your body for the rest of your life. Many people do not have symptoms and thus are unaware that they have the virus.
Long Answer:
One thing that distinguishes viruses in the herpes virus family from other types of viruses is something called latency. Herpes simplex and other herpes viruses have a way of creating a small but permanent colony of viral particles inside the body. This colony is often completely inactive “asleep” – but it persists for a lifetime.

Here’s how it works: once HSV gains a foothold, the virus begins making copies of its self and starts spreading. This can lead to a range of signs and symptoms, everything from subtle symptoms that go unrecognized to severe illness. In response, the immune system mobilizes its forces for an assault and limits HSV’s spread.

Whether there are severe symptoms or not, virus will persist in the body. To avoid the immune system, HSV will retreat along the nerve pathways, finding safe sanctuary in a nerve root called a “ganglion.” In cases of genital herpes, HSV retreats to the sacral ganglion, located at the base of the spine. In “oral” or facial herpes (cold sores), HSV finds its way to the trigeminal ganglion, at the top of the spine. In the ganglion, the virus remains inactive (“latent”) for an indefinite period of time.

Short Answer:
Approximately 50 to 80% of the population.
Long Answer:
About 50 percent to 80 percent of the adult population in the United States has oral herpes, with as many as 90% having the virus by age 50. Most people contract oral herpes when they are children from getting a kiss from a friend or relative.

Short Answer:
Yes, it is very possible that you could contract genital herpes from oral sex.
Long Answer:
Cold sores are caused by herpes simplex virus type 1. If you have oral-genital sex with someone who has a cold sore, this virus can give you genital herpes. The likelihood of this is particularly high during a primary outbreak. Washing with soap and water after a sexual encounter can help decrease the risk of transmission. Barriers such as dental dams can be used during oral sex to help protect against herpes and other STDs as well.