Diabetes Runs In My Family- My 84 Year Old Father

Diabetes runs in my family- my 84 year old father got it at age 43, my sister, who passed away last year from diabetic related issues, got it at age 15, and I am concerned some recent symptoms may be bringing diabetes my way. I have been feeling like I have the shakes, like low blood sugar issues lately- weak, rubber legs, unclear thinking. Not everyday, but 3-4 times over the past week. I have had those issues in the past but rarely. Is this a sign/ symptom of diabetes? I have been tested in the past with neg results.