I had a VERY well known exotics vet in my area probe 20 of my balls (before I learned how easy it was to do by myself). He got 3 of them wrong.

For example, one big super light dinker female a had purchased was sexed by him as a male. I was really upset by this so I asked several times if he was certain. He was absolutely certain it was a male.

Once I learned how to probe she without any doubt probed as a female.... she just laid her first clutch this season.

Where exactly are you located? Maybe you can find a BP.netter that knows what they are doing in your area that can give you a cheap second opinion.