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.
How many weeks pregnant am I? and learn your baby's due date so you can start planning key milestones. Please enter a valid date. Start with the first day of one period and count right up to the day before the first day of your next period. Count the first day of bleeding or spotting as day one. The average cycle length is 28 days, but can range anywhere from 20 to 45 days.