I went for a routine physical and had labs done. My WBC count was 8.6 but my neutrophyll % was 75.4 and lymphocytes were 13.2% I was on nitrofurantoin for a UTI at time could this effect results?

Slightly abnormal. Normal WBC count is 4500 to 10000 ceels/mcl neutrophils 50 to 70% lymphocytes 25to35% your test is slightly abnormal and may be due to uti.But there is nothing to be alarmed about. Total WBC count is normal neutrophils are slightly high may be due to uti low lymphocyte count is due to high neutrophiles discuss your result with your doctor who ordered the test.
Yes. An active infection or inflammation in the body could increase the polymorphonuclear cell percent age in your blood count. Repeat the CBC and differential cell count 2weeks after you finish your treatment.