Welcome to testmy.net jayartibee, you can start out by reading this , which is a legitimacy statement from the site owner. I'm sure he'd come in and have something to say to help you understand a bit more.,
In the mean time , have you tested from the three available test sites that testmy.net offers ? As at times of heavy network traffic in different parts of the US, you can and will see slow downs. The selection of servers can be found in testing area of the download and upload sections.