I had IVF transfer on 9/26 and my first ultrasound was on 10/16 at this time they saw a sac measuring 3.9 x 4.4 mm. On 10/22, which would put me at 6 weeks and 4 days I had a second ultrasound and the gestational sac measured 9 x 8 mm but sac appeared empty. I also have a tilted uterus. What does ...