I don't think the passport you have is any different than the one issued to adults. The only way to tell whether you are one or not is to read your date of birth from it. The age requirement exists due to potential custody issues. As long as you are over 18 at the time of crossing, I can't see why it wouldn't let you through but if for some reason it doesn't, nothing bad can happen: you'd simply have to go to a manned gate or press a button for manual assistance. Try it.