Bleeding during pregnancy

Hi, has anybody experience po nag bleed po kasi ako . I am 12 weeks pregnant na pala. And nag spotting na dn, till i got to be checked via tvs ultrasound and there were no baby seen just the sac alone. There were also no embryo. And they indicated the age of the sac around 4 weeks lang and 6 days . But i know i am more than that long to be pregnant. The one who checked me said it could be an abnormal pregnancy or i was just too early. Pag uwi ko ng bahay sobrang dinugo na ako. Could it also be blighted ovum. I cant stop crying knowing a lot of mother like me are experiencing the same as i went through. Ano po ba dapat gawin ? I am really confused what to do next. Should i wait for the sac to pass on me?