Blood levels of any substance changes regularly within a matter of hours. Given 20 days, even your LDL levels can normalise with or without treatment. In this circumstance, I would recommend you to do life style modifications like low carb low fat diet, moderate exercise, etc. After 3 months repeat Lipid profile and if deranged, go for initiation of lipid lowering drugs therapy after proper consultation.

Hello.. Was it a routine blood test as part of a package?  Was it a fasting lipid panel? (Did you eat anything before test). Because fasting/non fasting sample can make a difference.. Otherwise there shouldn't be much difference in the result after 20 days. What was the reason for repeating tests, do you have history of high LDL or family history of cholesterol? Thyroid issue, Diabetes or high blood sugar?