Mother:
Your nausea may actually get worse this week as your hormone levels rise. Remember it's called morning sickness, but it can strike at any point of the day. Your breasts may tingle, feel heavy, the areola (dark nipple portion) may become darker.
Avoid changing cat litter for there is a risk of toxoplasmosis. Let someone else do this duty for while. Toxoplasmosis can cause pregnancy problems and problems in the newborn, but most women who have cats have already had toxoplasmosis, and just believed it to be the flu. So don't get rid of the cat, just let someone else change the litter.
Baby:
This week is another busy one for your baby. By the end of the week your baby will be 4-6 mm Crown to Rump (CR). The larynx starts to form as does the inner ear. The lining of the placenta begins developing but the placenta will not take over production of the hormones until about week 12.
The heart is bulging from the body and blood circulation is well established. Upper and lower limb buds will appear this week. And the primordia of the liver, pancreas, lungs, and stomach are evident. Transvaginal ultrasound can pick up 86% of the fetal poles with heart motion, and 100% of the yolk sacs at this point.
Twin Tips:
Nausea and vomiting may be multiplied if you're carrying more than one baby. Though the standard remedies can still be helpful.