You mean "last star" because it is so blight it's still shining in the sky even dawnlight before sunrise is taking over the sky, right? So it has to be one of the Planets, which is quite likely Mars and may not Venus. Many people tend to believe Dawn Star and Evening Star are same. Not so. Evening Star is Venus whereas Morning Star could be Mars.
However, as you know, these are not Stars. They both are Planets, and their movements in the sky is, unlike Stars, very irregular. So Mars can be Evening Star, as Venus can be Morning Star. This is quite puzzling question to me just as it is to you.