i had them heaps with DS2- it freaked me too- i had them full on at 36 weeks for 26 hours- it got to the stage that the OB sent me to go and have CTG to make sure bubs was Ok as it had been going on for a while!
they subsided by themselves but they were comingt 10 mins apart at some stages

i went on to have boof a week later and when labour started the cx were 5 mins apart from the start!!!
so be aware that when it does start- it could come on quick
i had first cx at 8.45am, went to hossy at 12pm and was 3cm dilated and cx were 1 min apart - fully dilated at 2.45pm and had him at 2.54pm that same day after 3 pushes!! EASY!!
not long now girls