PGP - Encrypted content length does not match

Hi everyone, 

I'm analyzing PGP. I have encrypted one file without zipping and i have used passphrase to encrypt, so S2K algorithm will process. However, according to openPGP format, it should be in this format:

34-byte random value (Block size + 2) + plaintext + 2 byte MDC tag + 20 byte MDC value

For my example, plaintext's length is 35 byte. Its extension is txt, so it equals to the length of file. As a result, total amount of encrypted value should be:

34 + 35 + 2 + 20 = 91.

However, my encrypted file has 94 byte content. Do you have any opinion where these 3 bytes come?

Also i have tried 3 more files to check that it has always extra 3 byte or not, however it changes for each one.

Regards.