The kidney is not one large filter. Each kidney is made up of about a million filtering units called nephrons. Each nephron filters a small amount of blood. The nephron includes a filter, called the glomerulus, and a tubule. The nephrons work through a two-step process.
Generally speaking, first babies tend to engage from about 34 weeks to 36 weeks. However, some babies only engage once labour starts. Try not to worry, though. Even if your baby hasn't engaged by the time labour starts, in most cases, it's not a problem.
Seeing a pre-marital counselor might help. That said, Goldsmith says you shouldn't rush a wedding either. He recommends you be engaged for a minimum of six months before you get hitched to give yourself time to get settled into the idea of happily ever afterâand to make sure your guy doesn't turn into a groomzilla.