When we starting doing regular model shoots a little while ago, I was very good at staying in touch with the models, agreeing what we would be doing and confirming the date/time regularly.
The ones I had booked a little further out did not get the same degree of attention and, as one might expect, they have not turned out so well. We have been very busy at weekends so that has not been such an issue. I am sure I could have filled all the shooting slots we have if I really wanted to.
There is a principle though that if you are doing a commercial/important shoot, you should use a proper agency as they will always get a suitable model to you (not always the one you were expecting perhaps if s/he is ill or called away to a family emergency, but someone similar enough to complete the brief). With TFP (trade for picture) though, you always run the risk of someone not turning up especially if their are relatively new and do not have a strong track record.
I have been pretty rough this weekend anyway – asthma is bad. Not unusual when the weather turns. Stay warm, plenty of vitamin-c, and relaxing a little should help (I know from past experience that if I just keep going, it will get worse and worse).