her period could be delayed for any reason. could be stress, could be that it is taking her ovary longer to ovulate... if she is 3 weeks late and an ultrasound showed nothing, i would think she isnt pregnant. you should call the doc and ask if they can fax some bloodwork paper to your nearest hospital annex to check her level of pregnancy hormone.

also, about the retroverted uterus... i found out a few months ago that i had a retroverted uterus. it is nothing to worry about, it just means it leans backwards towards the colon instead of forward toward the bladder. she can still get pregnant! i had a son 7 years ago and am now pregnant with my 2nd baby. i have heard that it can lead to miscarriage if it doesnt start tipping forward during the 1st trimester... but thats just something i read online when i found out i had a retroverted uterus. my baby doc hasnt said anything to me about that since i got pregnant... so it may just be jibber-jabber.

was the drug they gave your wife called provera?? if it was, she should take it. i had a miscarriage back in february and thats what they gave me because i had some complications and the bleeding wouldnt stop. i took it, the bleeding stop, and then a few days later i got my period. then 2 weeks later i conceived again and now i have a healthy baby growing in there =)

good luck!