Your baby this week
Your baby is about the size of an apple — roughly ten centimeters, about four inches from head to bottom, and weighing around seventy grams. The legs have now grown longer than the arms, all the joints move, and your baby is busy practicing breathing movements, swallowing amniotic fluid, and sucking — some babies have already found their thumb.
The sense of the week is light: your baby's eyes remain sealed shut — they won't open for many weeks yet — but the retinas are already responding to light that filters through your abdominal wall, and babies have been seen on ultrasound shifting in response to a very bright light outside. Taste is joining in too: taste buds are forming on the tongue, the beginning of a system that will soon let your baby sample the flavors of your meals through the amniotic fluid.
Somewhere around now, your baby may also begin to hiccup — the diaphragm practicing, in effect. You almost certainly can't feel them yet; later in pregnancy they may arrive as gentle, rhythmic little taps. The ears are moving toward their final position, the bones keep hardening and are now visible on ultrasound, and fine lanugo hair is spreading across the body.
Your body & symptoms: hello, stuffy nose
The likely star of your week fifteen is your nose. A stuffy, congested nose — sometimes with the odd nosebleed — is one of pregnancy's most common and least glamorous symptoms; it even has a nickname: "pregnancy rhinitis." The cause is plumbing: your blood volume has climbed significantly, and that extra blood flow swells the delicate membranes inside your nose — and your gums, which may bleed a little when you brush; also common, also hormonal.
Saline spray or rinse, a humidifier by the bed, staying hydrated, and propping your head up slightly at night help many women. One caution: many over-the-counter decongestants aren't the default choice in pregnancy — check with your doctor or pharmacist before using medication, even the familiar stuff. Elsewhere, your bump is becoming a real presence, heartburn may be starting its slow climb — smaller, more frequent meals and not lying flat right after eating are the classic countermeasures — and the skin across your belly may stretch and itch: moisturizer there is comfort, not vanity.
Sleeping positions: practice season
Later in pregnancy, many doctors recommend side-sleeping — especially as the uterus gets heavy — because lying flat on your back for long stretches can, for some women, compress a major blood vessel and reduce blood flow, leaving you dizzy or nauseous. At fifteen weeks your uterus isn't heavy enough for this to be a real concern, and if you wake up on your back, nothing bad has happened — just roll over.
But habits are easiest to build before they're needed, so this is your practice season. The classic setup: lie on your side — the left is the one most often mentioned, though either side is fine — with a pillow between your knees to keep your hips stacked and your lower back happy, and a pillow or small wedge tucked slightly under your bump as it grows. Some women swear by a full body pillow; others build the same fortress from ordinary pillows. And for stomach-sleepers: while it's still comfortable, sleeping on your stomach is generally considered fine in early and mid pregnancy — your body and your bump will retire that position naturally, with plenty of warning.