Your luteal phase is the days between ovulation and the 1st day of your period. In order to calculate your luteal phase, you need to know the day that you ovulate. For instance, last month i got my period on August 3rd, and ovulated on on August 15th, and got my period August 28th. That means my luteal phase is 12 days long, counting from the day after ovulation, to the last day before my period came. Once you know when you ovulate, it is then possible to figure out your luteal phase. A typical texbook example would be the 28 day cycle. Meaning, you ovulate on day 14, get your period on day 28, making your total cycle 28 days long, and the luteal phase 13 days. Sooo not the case for many women. Your luteal phase almost never changes. Meaning, the day you ovulate determines how long your cycle will be. If you ovulate later in any cycle, in turn your period will be late. Women normally ovulate during mid cycle. Also, not the case for many women. Women that have longer cycles, ovulate later. Women who have shorter cycles, ovulate earlier. If you ovulate mid cycle or later you would be ovulating around cycle day 20, which would be September 3rd, and got your period on Sept 16th, your luteal phase would be 12 days long. Chances are with a 33 day cycle, you may be ovulating right now, so start baby dancing.
As far as the leaking, it's the ejaculate leaking out, not the actual sperm. Trust me, sperm are very clever, and they are already swimming to their destination by time the ejaculate leaks out. This will not prevent you from getting pregnant.
As long as ovulation has not been confirmed, then keep on having sex. Better to cover all the days then to be sorry. Good luck to you and lots of baby dust :)