EldonCards may not work as well on fetal bloodI, too, am so sorry to hear about what you went through.
In the hopes of helping others, I'd like to point out that EldonCards are marketed for "educational use"; specifically NOT to determine suitability for blood transfusions, etc.
That said, I realize many midwives use this product to determine whether a mother has rH negative blood and so is at risk for rH sensitization. When used properly, on an adult woman's blood, this is probably a reasonable approach. Should a woman test rH negative, she should receive Rhogam to prevent problems with future pregnancies. Most rH-positive women will test positive using Eldon cards. A very few will not -- they are considered "weakly positive" -- so any "iffy" Eldoncard test should probably be confirmed with a blood test at a doctor's office or hospital lab.
In your case, your midwife realized you are rH-negative. The problem may have arisen from your midwfe using EldonCards to determine your baby's blood type. Unfortunately, baby's red blood cells are fundamentally different from adult blood cells; we use these differences in tests like Kleihaurer-Betke to differentiate baby's red blood cells from mom's in mom's own veins.
To my knowledge, EldonCards have not been tested on, and are not FDA approved for, fetal blood type or rH determination. I work a great deal with "traditional birth attendants", who are midwives who learned their skills from their families or friends rather than becoming a certified nurse midwife or certified lay midwife. I ALWAYS stress the importance of providing Rhogam to rH-negative mothers without relying on EldonCards to type the blood of baby. If you want to avoid the expense (~$100) and hassle of Rhogam, you need to have baby's blood tested in a lab that can handle it. I offer to order these tests for local midwives (at no financial benefit to myself), or the local public health nurse can arrange it.
I wish you all the best in the future should you attempt future pregnancies, and I fervently hope no one else suffers as you have....