SetFilePointerEx with WriteFile and ReadFile

Question

#include <stdio.h>
#include <windows.h>
#include <stdlib.h>

/* Maximum size plus one */
#define MAX_BUF_SZ 101

int main(void){
    char readBuffer[MAX_BUF_SZ];
    DWORD bytesRead;
    char buffer[MAX_BUF_SZ] = "Test string";
    DWORD bytesWritten;

    HANDLE fh = CreateFile(("newfile.txt"), GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);

    if(fh!=INVALID_HANDLE_VALUE){
        printf("File opened for reading!\n");
    } else {
        printf("File not opened for reading!\n");
        exit(EXIT_FAILURE);
    }

    if (WriteFile(
        fh, // takes a file handle
        buffer, // a buffer
        strlen(buffer), // length of buffer
        &bytesWritten, // pointer where you want to store the number of bytes written to the file
        NULL // OVERLAPPED struct, setting to NULL
    ))
    {
        printf("File written to.\n");
    }else{
        printf("File not written to.\n");
    }
  
    /* Retrieves the size of the specified file. */
    LARGE_INTEGER moveTo;
    LARGE_INTEGER size2;
    
    GetFileSizeEx(fh, &moveTo); 
    moveTo.QuadPart =  11 * -1;
    printf("The file size is %lld bytes\n", moveTo.QuadPart);

    SetFilePointerEx(fh, moveTo, &size2, FILE_END);

    
    if(ReadFile(fh, readBuffer, sizeof(readBuffer), &bytesRead, NULL)){
        printf("File successfully read!\n");
        printf("%d bytes read.\n", bytesRead);
        
        //readBuffer[(bytesRead / sizeof(char))] = ' ';
        printf(("%s\n"), readBuffer);
    }

    CloseHandle(fh);

    return EXIT_SUCCESS;
}

This is my code. The goal here is to create a file, write a string to that file, then read the contents in that file. I learned that I need to use SetFilePointerEx to reset where the file pointer points to (I want it to point back to the beginning). However, this is my output:

File opened for reading!
File written to.
The file size is -11 bytes
File successfully read!
11 bytes read.
Test string@

I get an extra character and Im not sure why. Am I setting/using up SetFilePointerEx correctly? Do I even need to use SetFilePointerEx