The twins are now both the size of an olive!
9 weeks
Taken from babycentre.co.uk:
By the end of this week, your baby measures about 2.3cm in length and weighs less than 2g. His eyelids, now completely covering his eyes, are fused and won't open until week 26. Tiny earlobes are now visible.
Your baby's essential body parts are accounted for, though they'll go through plenty of fine-tuning in the coming months. Already he looks more like a tiny human being. His wrists are more developed, his ankles have formed, and his fingers and toes are clear to see. His arms are growing longer and bend at the elbows. Now that your baby's basic physiology is in place, he's poised for rapid weight gain.
Your baby's essential body parts are accounted for, though they'll go through plenty of fine-tuning in the coming months. Already he looks more like a tiny human being. His wrists are more developed, his ankles have formed, and his fingers and toes are clear to see. His arms are growing longer and bend at the elbows. Now that your baby's basic physiology is in place, he's poised for rapid weight gain.
Though it's not yet possible to tell the sex of your baby by ultrasound, his genitals have begun to form. By now the placenta has developed enough to support most of the important job of producing hormones. The placenta is also making nutrients for your baby and getting rid of his waste products.