If you moved your old bed into the new place, rule that out. Check for mold in the basement, bathroom, or crawl space.
Also, if new carpet has been laid recently, some of the adhesives can cause sickness.
Air purifiers help, but if it's mold, you need to get rid of it. Bleach will kill it but this is a job for pros because special breating equipment is needed.
Other tips- change the filter in your furnace, get a Carbon Monoxide detector, also check the USGS site to see if Radon is present in your area. If it is, have a radon test conducted. (this is not as likely because Radon usually take a while before it's effects are noticed.)