In the United States the electoral college system is what is used to elect the President. So technically speaking, your vote is not counted toward the candidate but is a vote for your electors. It's actually quite complicated and I don't necessarily agree with the process. I am also not completely studied up on it so maybe my disagreement is unfounded.
Here is a link (with many other links) that explains it pretty well.
http://www.archives.gov/federal-register/electoral-college/about.html
Also, voting is anonymous so they know you voted but not who you voted for, hence no service provided for checking that your vote was already counted. (To answer your question. :)
Also, A number of states have enacted requirements for mandatory manual audits. Here is a link to information and an interactive map to view specific information on different states.
https://www.verifiedvoting.org/resources/post-election-audits/
The United States does not have a national Election Code that governs the tabulation and publication of all election results, although general provisions of the U.S. Constitution apply and, in limited circumstances, so do a few federal laws.
In practice, elections for local, state, and federal office are conducted primarily by local election officials in the nation's counties, parishes, and independent cities or townships. These local election officials, in most states, exercise broad authority. Despite their relative autonomy, these local election officials are bound by their respective state statutes regarding the conduct of elections. These statutes include the manner in which votes are to be counted. At a minimum, the county’s obligation to count and report the vote accurately, and in an objective and impartial manner, is implicit if not explicit in law.
Full Document Here ...
http://www.eac.gov/assets/1/Documents/Tabulating.Election.Results.doc.4.12.12-rbw-edits.pdf