Confusion:should i keep preparing head first pmp book (which covers PMBOK 5th edition) or wait for sixth edition?

Please clarify my Confusin:

Should i keep preparing head first pmp book (which covers PMBOK 5th edition) or wait for sixth edition as i plan to appear in first quater of 2017?

There will be more PMBOK 5th edition reviewer. - Steven C Wyer