Bloodwork showed wbc of 15.7 and nuetrophil left shift of 12043..feel fine .should i be worried?

The most common: Reasons for a neutrophilic leukocytosis would be bacterial infection or stress of some other illness. Also seen in heavy smokers and with some meds. If you are ok then a follow-up in 6-8 weeks would be fine.

See below...: You may have an infection or an inflammatory state even in the absence of symptoms. If you do have some symptoms, i recommend repeating the CBC to make sure values are returning to normal; however, other explanations are possible including serious diseases like leukemia, more specifically chronic myelogenous leukemia. Please consult your doctor or a hematologist.