Do not rush to amend - no hurry. You have 3 years to amend and amended returns are taking 4-6 months or longer to be processed so waiting a few weeks will make little difference and amending too soon might just compound the problem. (If you amend today you probably will not see the results until August or September).
-- If accepted you should *wait* until your return has been processed and you receive your refund or conformation that any tax due has been paid. (If you file an amended return while you first return is being processed it can cause extended delays for both returns if two returns are in the system at the same time). In addition, if the IRS makes any change on your original return, you might end up having to amend the amendment – a sticky process that can take a year or more).
-- Then you can start the amend process.