I spat some pinkish saliva couple of times in the past 2 weeks have been smoking for some time but quit 6 months ago i have occasional chest pains what might be the reason ?

Gum disease: Blood in saliva can be an indication of gum disease. Smokers tend to bleed less, so your recent smoking cessation (which is admirable) may have allowed some of the symptoms of the gum disease to become more evident. See your dentist to determine if you have periodontal disease or if it is another condition.

There are many...: Blood can make its way into the saliva from almost anywhere in the respiratory or upper digestive tracts. This symptom is most commonly from either gum disease or minor mouth injury, but may arise from more serious conditions, including esophageal erosions or varices, lung or bronchial infection, or even malignancy. If your dentist can't find its source, bleeding should be investigated by your md.