You begin to have a "pregnant glow" by the time you are 12 weeks pregnant. Increased blood volume and pregnancy hormones work together to give you that glow. The greater blood volume brings more blood to the blood vessels and hormones increase oil gland secretion, resulting in a flushed, plumper, smoother skin appearance. The increased oil gland secretion can also cause temporary acne.
Some body changes that occur during week 12 of pregnancy include morning sickness diminishing or disappearing, fatigue disappears or diminishes, and your waistline expands. You may experience headaches or lightheadedness.
Your placenta will take over the production of hormones around this time. Your risk of miscarriage is reduced even further this week.
Your uterus has risen above your pubic bone, and your obstetrician will be able to feel it during an abdominal exam. Around this time, you may begin to show. For first-timer mothers, "showing" may occur a bit later, as strong abdominal muscles hide your pregnancy longer.
By the time you are 12 weeks pregnant, your baby is about 2.5 inches long and weighs approximately 0.3 to 0.5 ounces. Your baby's brain continues to develop, and tiny fingernails and toenails start to form. Vocal cords are formed this week, which is the last of your first trimester.
Your baby's kidneys are functioning, as is the liver. They thyroid gland and pancreas are also complete. Your baby is now passing urine and the gall bladder secretes bile. After swallowing amniotic fluid, your baby will now be able to pass it out of the body as urine. A skeleton made of cartilage is forming.