Yea with my 1st people kept telling me the same thing & I was not getting it. As crazy as it sounds when it's real u will no. They will be at very regular intervals and the pain is extreme. I just remember I kept saying o wow this really hurts no words could have prepared me for this. As well as I agree with everything kori353 stated.
They come in regular intervals, get longer, and closer together when it's real labour. When it's false labour they are very irregular. They also will usually ease up when you walk whern it's not the real thing.