查了一些语法著作，以下出处应该算是比较权威，供参考：
1.《英语在用——剑桥中级英语语法》第109节指出：
Note that probably goes before the negative. So we say:
I probably won’t see you. or I will probably not see you. (but not “I won’t probably.”)
2.《牛津英语语法指南》第25节指出：
We sometimes put an adverb after the subject and before the verb phrase. This happens especially with a negative (probably doesn’t) or when there is stress (really are).
It probably doesn’t matter very much.
3.《牛津实践语法》（第2版）第113节指出：
In a negative sentence, probably and certainly come before won’t, didn’t, etc.
We probably won’t get there in time.
I certainly didn’t expect a present!