When the placenta takes over

Sara
Ladies! Strange question but did you actually 'feel' when your placenta took over? Some say it happens week 12, some disagree. I'm still sick at week 12, but my midwife says it'll take over week 14-16. So does anyone actually 'feel' it happening? Is there a cramp or perhaps some surge of energy or indicators? Right now I need encouragement! We can do this girls! Thanks!