 [ Symptoms ] what can i expect during week 17 of my pregnancy [ Disease ] baby  your baby now about in its 15th week of development measures about 4 4 to 4 8 inches from crown to rump and has doubled in weight in the last two weeks to about 3 5 ounces fat begins to form helping your baby is heat production and metabolism the lungs are beginning to exhale amniotic fluid and the circulatory and urinary systems are working hair on head eyebrows and eyelashes is filling in mom to be  you are showing more now with an obvious swelling in your lower abdomen a five  to 10 pound weight gain is typical by now you also may be noticing an increase in appetite tip of the week  change positions slowly especially when you move from a lying down position to sitting or from a sitting position to standing to avoid feeling dizzy or faint if you feel lightheaded sit down and lower your head or lie down for a moment