Lady T, it is not time to give up hope. Did they do an abdominal or a transvaginal ultrasound. The abdominals are less reliable, but transvag isn't perfect either.
FYI, I was told I was 7w3d pregnant but the sac was empty. All that week I waivered between having lots of hope, based mostly on superstitious "signs" that I still believe, and having the feeling that there was no hope, mostly because my boobs hurt less and my nausea was better. Well, lo and behold I was actually 1 week earlier than the sac measured at the first US. The second US showed a healthy 7w2d fetus, a week later.
I am 15 weeks now with a normal looking, growing, moving baby. Not everyone has the same outcome as Chrystal and I, but I think it is too early to give up hope. You only need to do something to "flush" if you are having signs that your own health is in danger, like fever (could indicate an infection). Until then, it is your own personal comfort level that will determine how long to wait. Best of luck, and have sequential HCGs drawn.
No fetus seen @ 7 weeks 2 days by radiologist