Hatchlings can be popped to determine male or not, but this is not 100% accurate, or safe! Adults can be compared together for tail size. Probing is quite safe IF you know what to do, I am sure there will be someone local to you who could probe for you though. It won't hurt the snake, unless done wrong of course.
What is the problem getting it probed? I probe all my corns and have never had a problem with any of them. So long as it is done my someone who knows what they are doing, it should be fine. If it is still quite small, you may be able to get it popped.