Girls, hi. What week does the training contractions start? I don't und…

Girls, hi. What week does the training contractions start? I don't understand what happened today ?‍♀️?‍♀️?‍♀️? One time maybe two minutes it pulled my belly then let go about five minutes again for two minutes it pulled my belly. Let go and then the third time exactly the same and everything went away. And I don't know what that was.