There can be a knack to cabling, most people get it wrong the first few times, assuming that you've got he wire in the correct order my tip is to apply forward pressure while you crimp it, this makes sure that all the wires reach the end of connector.
However if you havn't got a tester for the sake of a couple of £'s you'd be better of buying a patch cable, at least you know that the connection will work then. If it doesn't then it's not the cable thats the problem, however use your own and even if you have wired it right - how can you be sure if something else is causing the problem. You'll always doubt the cable.
The more you know, the more you realise there is to know....
CCNA MCP