From what I understand about them Min they actually start at around 5-6 weeks but are usually felt sometime after the 20 week mark. I've read that its completely normal and you shouldn't be concerned unless you feel them more than 4 times an hour, they're painful or there's any bleeding/spotting. I dont think it means that bubs would be more likely to come early. I havent felt any yet but I suppose its only a matter of time! All the best with the rest of your pregnancy