How to read my internet speed test from speedtest.net?

I just got Verizon Fios and I'm supposed to have the 20Mbps/5Mbps internet speed. I don't know what that means though. I knows its not the slowest option they offer but not the fastest. I went to speedtest.net and ran their test and my results are: 5.12 Mb/s download speed and 3.32 Mb/s upload speed. Doesn't 20Mbps/5Mbps mean my download speed should be 20 and my upload speed should be 10? I have a feeling I'm not getting what I paid for. I selected the Flex Package through Verizon if you want to look it up for better understand what I'm saying. Any help is appreciated.