The Elections Office has sent letters to voters whose ballots lacked a signature, didn't declare a party, and/or whose signature didn't match the one on file. The votes will count if the voter corrects these mistakes before March 19, 2020.
Voting for a candidate who had dropped out is not a correctable mistake.
To check that your ballot has been processed. Go to https://voter.votewa.gov/WhereToVote.aspx
After you enter your name, birthdate and click submit, you are taking to a page showing your registration information.
In the left sidebar is Ballot Status. Click on that and you will see the status of your ballot.
For more information visit the Elections Office's webpage.