Question about blood glucose meter result.

I'm new to this so I have a question. I'll be seeing my doc Tuesday and will ask him then but wanted to see if you ladies had any input before then.

After dinner I tested and got a result of 146 - the highest number I've ever had. I kinda freaked. I took a breath, and did the test again ten minutes later and it was 105.

Why would there be such a large discrepancy over such a short period of time? Should I be concerned about that spike ( my after lunch was 105) ?

Thanks for any advice you might be willing to share.