Week 9 During Week 9 of pregnancy, or 7 weeks after conception, bones have begun to form. The embryo's arms are growing and can bend at the elbows. The legs, hands, and head can move. Toes are beginning to form and upper and lower eyelids are in place. The heart has 4 chambers and is nearly complete. Production of cerebrospinal fluid has begun. The embryo can hiccup. It is close to three-quarters of an inch long.