In 'classic' cases, they can be like what you describe. However, for me, personally, my contractions started out three minutes apart and 60 seconds long or so. I had my baby two hours later. My midwife almost didn't make it because I was expecting contractions to be like what you described so for awhile wasn't sure if I was 'really' in labor, so I waited forever to call her. So, there is a wide range of normal and it's probably best to listen to you body (I know, easier said than done sometimes!

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