So you said that u get the sac but no growth so I googled to try to come up with something since with doctors it's always waiting and waiting u know.. So what I read is blighted ovum.... Where this could be happening because of hormonal Imbalance or genetics.. I would ask your doctor to check your hormonal level and maybe ask your husband if he's into getting an semen analysis done. Just to be safe. I remember my doc telling me to have my fiancé checked because his Soren good be good but abnormal shape. So idk just read the pictures and let me know if it seems like possibility of what's been happening? I had my prolactin with (hormone) level checked before and I wasn't getting pregnant because mine would always be high. I would ask for her to check everything prolactin, progesterone u name it.