Is my internet dl speed working properly?

When I go on my laptop, I would download something it it would say 350kbps at the start of the download. Then, a while later it dies down to 60kbps. And now, its happening when I open videos on youtube, or start downloads. At anytime!!! And sometimes It would steadily stay at 150kbps. Im with rogers. Am I suppose to have 60kbps dl speed? Or maybe my cord cant handle all the speed. Its w/e I just need to know why it does that and if I am getting lower dl speed then I should have. I dont know what my parents put the plan on, but im pretty sure they are not paying for 60kbps on rogers