i had done my ivf june 20th embryo transfer .had bleeding on 18thjuly for two days with spotting no pain or cramps .had repeat scan tvs today on 6 aug.they saw only a 12mm sac no yolk sac has been seen...this scan is repeated after a week.still same 12mm sac seen.am using progestran suppostries soon after ivf..my bhcg done last week was 0000..today nurse told me to stop using utrogestran as they cant see ant yolk sac..but am not sure..still having pregnancy symptoms no spotting at all.had vaginal examination last week the dr said my cervix ix healthy and closed.. plz plz tel me is it normal to hav sac 12mm at this week? done ivf from pakistan am uk at the moment...v tense plz do reply