Your baby weighs about 10 1/2 ounces now. He's also around 6 1/2 inches long from head to bottom and about 10 inches from head to heel. (For the first 20 weeks, when a baby's legs are curled up against his torso and hard to measure, measurements are taken from the top of his head to his bottom, the "crown to rump" measurement. After 20 weeks, he's measured from head to toe.)
He's swallowing more these days, which is good practice for his digestive system. He's also producing meconium, a black, sticky by-product of digestion. This gooey substance will accumulate in his bowels, and you'll see it in his first soiled diaper (some babies pass meconium in the womb or during delivery).
Congratulations! You've hit the halfway mark in your pregnancy. The top of your uterus is about level with your belly button, and you've likely gained around 10 pounds. Expect to gain another pound or so each week from now on. (If you started your pregnancy underweight, you may need to gain a bit more; if you were overweight, perhaps a bit less.) Make sure you're getting enough iron, a mineral that's used primarily to make haemoglobin (the part of your red blood cells that carries oxygen).
During pregnancy, your body needs more iron to keep up with your expanding blood volume, as well as for your growing baby and the placenta. Red meat is one of the best sources of iron for pregnant women. Poultry (especially the dark meat) also contains iron. Some common non-meat sources of iron include legumes, soy-based products, spinach, prune juice, raisins, and iron-fortified cereals.