Hi there, if your dates have been wrong then it may have been too early to see anything via ultrasound, I have to ask, did they do it abdominally or vaginally the scan? if it was a transvaginal scan and they didnt see anything and you are sure of your dates, then im sorry but the pregnancy has most likely failed, they should be able to see the sace clearly and also the fetal pole and in most cases a little heartbeat by 6.5 weeks, again if the scan was abdominal and your dates are a little off the pregnancy may still be fine and the bleeding/spotting you have been experiencing could be the implantation bleeding coming out. let me know please? good luck to you and all the best :)
i agree with above . the gestational sac should be visible. Good luck
When you say they couldn't see anything, do you mean they couldn't see a heartbeat or any sign of pregnancy? At almost 7 weeks, I think that a gestational sac at least should be visible, but it is likely too early to see heartbeat.