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.
Based on a 28 day cycle, a woman will typically ovulate around day 14, or halfway through the cycle. Women with a longer cycle, say 35 days, will get pregnant around day 21. Once a woman knows when she ovulates, itâs easy to figure out her fertile days.