The uterus is the remarkable organ that serves as your baby's home during pregnancy. After delivery, it will still weigh as much as 0.7 kg (1 1/2 lb). If you press the center of your abdomen, your uterus will feel like a firm, grapefruit-sized mass.

The process by which your body returns to its prepregnant state is known as involution, and shrinkage of the uterus to its original size is a naturally occurring part of this process. To assist in the process of shrinkage, your nurse or midwife may knead your uterus during the first hour after birth. Within a week of delivery, you probably won't be able to feel your uterus when you press your belly, and by the end of the sixth postpartum week, your uterus will have shrunk to about 60 grams (2 oz).

During this time, the uterus will also continue to shed the lining it used to support pregnancy. This results in a discharge (known as lochia) that is bloody for the first 3 or 4 days after delivery, then lightens to a brown or yellowish color over the next 10 to 12 days. This discharge is a perfectly natural occurrence and shouldn't cause you alarm.

You may, however, experience some discomfort due to the contractions that accompany uterine involution. If so, consult your physician before taking any medicine, including aspirin.