Sara, sorry for the confusion here on my part, I loaded the test program you said to use and I get the same result, failed to read sensor on the Serial monitor. Confused by some of the instruction, when it says DHT pin 2 I am assuming it wants D2 or is it looking for a GPIO pin? 
I have used this same DHT11 on other projects you have here and it always worked so I am really having a hard time thinking that it is a sensor issue. Thanks