That sounds like what I had for a few days before DS2 was born. I was also worried that I wouldn't recognise labour when the time came, as I didn't the first time LOL and my first labour was 8 hours, even after the epidural slowed it all down. But the second time I did know straight away once the real thing started. Just as well too - it was a 3 hour labour and I didn't make it to hossy with much time to spare!

I think, if you allow it to, instinct tells you when it's real. Also watch out for really intense pains that are more or less regular and don't stop when you rest. Mine were waking me up when I was trying to nap. People will tell you that they need to increase in intensity and/or frequency, but I found that with my quick labours, they just started at the increased intensity and frequency to start with.