Did you print, sign and mail your Form 1040X? Did you mail it using a service that tracked it, like UPS or certified mail, so you know the IRS received it?
A 1040X cannot be e-filed. It must be printed and mailed. It will take about 3-4 months for the IRS to process an amended return. It is a good idea to use a mailing service that will track it, like UPS or certified mail, so you will know it was received.
Wait about 3 weeks from mailing and you can check the status of your amended return:
https://www.irs.gov/Filing/Individuals/Amended-Returns-(Form-1040-X)/Wheres-My-Amended-Return-1
https://www.irs.gov/filing/individuals/amended-returns-form-1040-x/amended-return-frequently-asked-questions