she loves me not 和she doesn't love me的区别

she loves me not 和she doesn't love me的区别
看到英文中说“她不爱我”很多都是说she loves me not,但是she doesn't love me这样也很常用,哪个是对呢?或者两个都对?它们有什么异同?遵守的什么语法?