Originally Answered: would you call this rapid weight loss and if so is it healthy?
Yes, you should be concerned, and depending on the reason and method of weight loss it could be unhealthy. It doesn't necessarily mean anything is wrong with you, but with rapid weight loss without being depressed, dieting, or exercise, usually means something else is causing it, and it could be a condition that needs to be addressed soon.
A lot of times people do change their diet, as far as the quantity, without really realizing it. However, it could be other issues such as hyperthyroidism etc.
You need to go to the doctor as soon as you can, call tomorrow, and have them do a physical. They will do a CBC (complete blood count) and possibly some other tests to rule out a few conditions. Make sure you tell the doctor exactly what you said here.
Seriously, call tomorrow or very soon. Hope this helps and good luck!