Victoria. I understand your situation. I once went on a business trip and parked my car at the airport for an early morning flight. I had to turn on the dome light to get all my stuff out of the car, and inadvertently left it on.
This did not occur to me until I was ready to check in that I had not turned it off… I called my wife to ask her to drive to the airport and turn it off. Luckily we had 2 sets of keys for that car.
Wife was not pleased, needless to say. On a Pontiac like I had there was no warning buzz to warn that the light was left on. And it takes about a day (24 hrs) to drain the battery. My trip was for 3 days.
You are right to suspect that you may have other parasitic losses. An important one could be the trunk light operated by a mercury switch that turns it on when the lid is raised. We had a gentleman with a Lincoln who parked on a steep driveway and kept losing his battery charge. When he parked the car in the opposite direction it battery stayed charged. It took the mechanics a while to figure that one out.