There is a directive in the MySQL configuration file that will allow you to search using 3 character words, but you will need root access to your server to change it. Most hosting companies do not give you root access.

ft_min_word_len=3

You will need to escape your search string with backslashes in order to search for words with escaped apostrophes. Do something like the following before you perform a fulltext search.

$searchString = addslashes($searchString);