I would maybe take the time to contact the web masters of the sites you had scheduled advertisements on. Explain the situation to them and see if they would be accomodating enough to push your ads back several weeks. 3-5 weeks is a pretty huge lag time. I was running 3 or 4 days behind a few weeks ago and got a pretty nasty email from a guy whose shirt hadn't reached him in 6 days. People want things NOW! or sooner if you can manage.