On the left side of my mouth on my gum it look swollen. it look very weird and won't go away .

Have it evaluated: Whether this is gum disease, a dental abscess, or something else is not clear from your description. Find a dentist & let them help you sort out a cause and treatment.

Swelling: Sorry, "weird" is not an diagnostic term. Any pain, bleeding, ora as in your case swelling, should be immediately investigated. Most (but not all) intra-oral swelling is caused by infection. Please call your Dentist for an appointment.