Sigh, I dont know how to calculate IVF pregnancy weeks. My LMP was 27 Nov 14, ET of 3d embryo was 18 Dec 14, bt 30 Dec 14. No heartbeat detected today and it measured only 3mm. Sonographer said 3mm is about 3 weeks only. 3 weeks what? Fetal age? too many lingo and concepts to grasp - not sure...