You're not my doctor, so how do you know?

I find the end of pregnancy very confusing. All the signs of labor that I've had for awhile are now seeming normal, so how do I know the true difference between "false labor" and "true labor". Usually, looking up information online has been a great help. The problem is that all claims about true labor are vague and finish with "everyone is different, so the best way to determine if you are in true labor (and your water has not broken) is to contact your physician. That's all great, except when your doctor has a day off. My doctor has Friday's off except if there is an emergency (such as a delivery). While filling out my Short Term Disability paperwork on Friday morning, I realized there was a full page that had to be filled out by my doctor. Oops! I went down to the doctor's office to drop it off and requested to ask to someone to help me with their suggestion of what the difference is between "false labor" and "true labor". The doctor that was filling in was one that sent me to the labor and delivery room last week when I was simply asking questions.. and when I said that I was just nervous, she had said "if you were truly nervous, you would already be on your way to labor and delivery". Anyways, this doctor came in and I was asking her for the differences so I could be more aware. Her first comment was "well, you are not in labor right now because you are able to talk to me". I was taken aback because I didn't say I was in labor, just wondering the differences. So I responded "ok, so pain where I can't talk.. what else?" Then she went on to say "you also aren't in labor because you haven't dropped at all". Once again, advice that made her look like she didn't care.. especially because I have dropped down four fingers width (from my sternum to the top of my bump, it has lowered the width of 4 fingers in the past week and a half). So I said "ok. Anything else?" She then said "if you are thinking you are in labor, you need to go to labor and delivery". I then had a little pregnancy hormone surge and said "I can't just go to labor and delivery with every inkling of suspicion because each visit there is $2500 since it is an outpatient procedure. That is why I am asking you what I should be aware of so that I will only go to the hospital when I am actually in labor". She said "well, better safe than sorry". The conversation was obviously going nowhere, so I just said "ok. Thank you for your help". At that moment, I had more love and devotion to my actual doctor. Even when I worry, my doctor will tell me what I need to know rather than tell me I'm being crazy and act like I'm just some elementary student who doesn't know anything.