Today I took my Evra patch off to replace it with another one but forgot and didn't put another patch on for 5 hours will this affect the effectiveness of the contraceptive

You may want to use a backup method of birthcontrol for the next little while ie) condom or spermicide better safe then sorry. Chances are you are OK to not worry... but like I said better safe than sorry!

And on another note... I didn't like the patch.. I found it fell off too frequently... I don't trust that method of control!