I am sorry to hear you are worried about your bitch. My name is Rebecca. I am a veterinarian and will do my best to help.
I just came online and saw your question; I am sorry you did not get help from an expert before now.
I usually consider labor to be starting, when the bitch starts pushing. What is she doing to make you think she is in labor, if she is not pushing?
How is she now?
I am in a different time zone; how long ago was 7 in the evening there?