Positive Ovulation Cycle for the Year

Here's my cycle for the year and corresponding positive LH surge.

2012 December 29 - day 14 - period Jan 13 (15)
2013 January 30 - day 18 - period Feb12 (13)
2013 March 2 - day 19 - period March 17 (15)
2013 April 6 - day 21 - period  April 21 (15)
2013 May 12 - day 22 - period May 26 (14)
2013 June 12 - day 18 - period June 26 (14)
2013 July 8 - day 13 - period July 24 (16)
2013 Aug 7 - day 15 - period Aug 22 (15)
2013 Sept 10 - day 20 - period Sept 23 (14)

In average my LH surge is in between 14th-15th every cycle. Somehow my ovulation day varies from day 13-22. It's hard when you are irregular you can't really tell which day. All I have been doing is using the ovulation predictor. The kit really helps big time as to when to BD and do the deed.