Your meters manual should have accuracy (usually at the end). If you tested at home for say 85 for the standards listed below, 20% of that would be 102. Given what Super_sally888 stated about that changes can happen. One thing I use to do was test right before (like when I sat down after checking in) and then compare.
Generic US standards: Acceptance criteria in ISO 15197, 2003 are that 95% of all differences in glucose values (i.e., between reference method and meter) should be within 15 mg/dL for glucose values less than 75 mg/dL, and within 20% for glucose values greater than or equal to 75 mg/dL.
could be that the home meter was not so accurate.
or could be that your blood sugar went up (it is possible), while you were waiting to go to the lab. Some people's blood sugar rises in response to extended fasting, particularly in the mornings.
Suggest you get an hab1c done. This will give you your average blood sugar over the past 3 months. Ideally the result is < 5.0. If it is higher than 5.0 then you need to start watching your diet etc. If it is over about 5.7 - 6.5 (depends on the lab), then you will get a diagnosis of diabetes.