So I thought I was 10 weeks today..but at my us the doc told me that there is a sac but no baby or hb. I had a a period in Jan. And that was the date that I calculated it off of. But I failed to mention that I had a light period in Feb. So with that being said I would only be 5 weeks..I need help! I'm at ftm and I'm just worried it'll end up in a miscarriage. Is an empty sac normal?