It is ok to use MD in many of circumstances. In fact, tons of Postdoc in medical school are MDs from China. Be confident. However, you also need to be careful to judge if your title will be helpful or not. Even many American are afraid to call themselves MD if they did not pass the certificate exam or they are not working in the medical field.

哦，是这样。多谢多谢！！

你写经历的时候要加年代的， 所以实际上别人是看得出来的。而且现在好像老美们都知道这回事，就这么写。你想有些国家Ph.D 只花两年，而我们要花5年以上，不也都通用嘛。
不过我是学了八年的，也只能说MD, 还老有人问我，是跟我们美国的MD 不一样的八？ 郁闷。