Mam: Pregnant 23 weeks (Baby 21 weeks)
Aches in the small of your back may continue
Aches in the small of your back may continue. Lie down, get massages, or use a hot water bottle or heating pad for comfort.
You expected your belly to grow — and perhaps your breasts, too — but the following physical changes may take you by surprise. As with many pregnancy changes, hormones play a role in most of these alterations in your looks. 
- Thicker, more lustrous hair You're not actually growing more hair, just losing less than normal. During pregnancy, your body sheds hair much more slowly than it did before. After your baby's born, you'll start to lose this excess hair, sometimes in clumps.
- Faster-growing fingernails Your fingernails may grow more quickly than usual, and you may notice changes in texture. Some women's nails get harder, while others' get softer or more brittle. Protect them by wearing gloves in water and use a good moisturiser
- Skin changes Some pregnant women report that their skin has never looked better.
- Skin discolorations Increased melanin can cause splotchy patches of darkened skin on your face. These pigment changes may become intensified if you spend time in the sun so be sure to wear a good sunblock when out in the sun
- Larger and darker nipples and areolas You may find that your nipples and the pigmented area around them (the areolas) are getting bigger and darker. The little bumps on your areolas, known as Montgomery's tubercles, may also be more pronounced. These bumps are oil-producing glands that help fight off bacteria and lubricate the skin.
- Larger feet Your feet may go up half a shoe size or more from general swelling so wear comfortable shoes!
WebMD discusses week 21 - 25 in pregnancyfind out more
Babycentre discusses week 22 in pregnancyfind out more
Langmans Medical Embryology, Ninth Edition, TW Sadler, 2003find out more