I just donated blood and was told my total cholesterol was 172. A month ago, I had a cholesterol check and my readings weren t enough to show on the scan. I was told i didn t have enough cholesterol to register. I started taking fish oil and vitamin to help with it. Was my first test wrong and this is something I should be concerned about? I am not overweight . 130lbs 5 8 . I enjoy exercising and eating healthy.