Its not too late to get more bitcoin if you are sure you know what you wanted because if the fork is successful, you then get double bonus in the sense that more BCG belongs to you by only holding and aside that, it is expected that there will be increase in the price of bitcoin because a lot of people will be selling their BCG immediately to mop up the BTC available in the market thereafter, you can then sell to make money. But be warned that it is mere speculation that and its not expected to hold that way for certain.