pregnant or not

Question
hi i breed my mare 19 aug 07 and 28 days later she was scanned not in foal but the vet could see a ruptured corpus lithiem and said she would be ready to cover next day. however as it was late in the season i decided to leave it till this year.and she never did show a season or has shown one since now seven months on the mare to my horror the mare looks in foal her abdomen has dropped and is much larger than it should be she has no other weight gain else where and has gone through the winter supplemented with hay only. i called my vet and he was unable to carry out a blood test or a scan as the mare was to distressed by his presence. i then carried out a foal proof urine test on her which showed neither a clear positive or negative result. movement in the abdomen is visible especially if the mare is eating or drinking the increase in her belly in the past three weeks is far greater than i would of expected if she was scanned in foal with the scan showing negative at 28 days and the urine test being inconclusive all indications head towards the mare not being in foal and she is booked into the stud again in four weeks to see if they can tease her into season. Is it possible for a scan to be missed at 28 days is it possible for a scan to miss twins and how accurate are these home pregnancy tests

Answer
Dear gemma,
         IT appears to be that she is pregnant, just by the increase in belly size and movement in the stomach. The only way to know for sure is to get a test, but as you have already tried that, I would just wait and see if she begins to produce milk. This could be a phantom pregnancy, but i doubt it with the movement. Try to put you ear to her side and listen, or feel for any movement.
michelyn