a tingling feeling in my foot. Diabetic Symptoms?

I'm 29. I have a tingling feeling in my left foot that sometimes goes up the ankle. Sometimes its a burning sensation and it seems more noticeable at night.There is a small dark spot on the bottom of my foot too. I don't urinate a lot though and I haven't had a weight loss. My dad has diabetes and I took a blood test for diabetes a few months ago and came out negative. Im freaking out. Help?