Hi Dj,
There are a number of reasons for this, some of which you can control and some which are completely out of your control. Before you continue, disconnect ALL phone equipment (including cables to your PC and router) and reconnect them. The action of doing this wipes the contacts inside the connector and can sometimes give you a better connection - you probably don't notice this at audio levels, but at high-frequencies such as those used by broadband, it can make a huge difference. This should at least ensure that everything is connected properly at your end. Next, test your speed by following the link below. Remember that the results of this are merely a guide and represent your machine's capability at that moment in time. Repeat the test several times to get a truer result, also try the test at different times of the day to minimise the effects of network density in your area. This advice holds true in the UK where I am based, and it probably does for you too.
Dwarf
Speedtest.net - The Global Broadband Speed Test