Is there a grace period after closing to back out of buying a home?
If you are referring to the Federal Right of Rescission period, it does not apply to purchase transactions. That is because the damages that could be done to other parties in related transactions exceeds the potential damages a buyer might receive. There are plenty of protections for buyers in the form of home inspections, appraisals, etc and those differ from the types of pressures that might have existing homeowners grant mortgages in refinancing transactions when perhaps the homeowners did not really want to give a security interest in their homes.
If there was something uncovered after closing, you still may have redress against the seller, Realtor or other related parties if there was willful intent to deceive. You should consult an attorney in that event.