Hello,
I haven't used it, but I think the monitor you have measures LH (luteinising hormone) and estrogen (not sure - think so though!). This gives it a good idea when you are about to ovulate.
Usually, well always really, your body releases a surge of estrogen and also LH just before you ovulate, ie the egg is released, ready for sperm to fertilise, whether they are there waiting already or about to arrive.
Your peak fertility days are the ones indicated, that means your monitor detected raised levels of these hormones in your urine. So it means it's the right time to have sex if you want to have a baby, those days it told you were 'peak fertility'.
Your luteal phase is the part between ovulation, which will have happened probably on one of those 'peak' days or possibly the day after, and your next period, and during this phase, the egg is travelling down your fallopian tube towards the uterus, either fertilised or not, and when it gets there it will either die if it isn't fertilised or it'll implant into the lining of the uterus and that means you're pregnant.
If it dies, the uterus will then get rid of all of it and start again. If it's implanted, (which will probably occur from about 6 to 12 days after ovulation/fertilisation), you won't have a period and that's that 
So the time between the day you ovulated and your next period is your LP, or Luteal phase, and with that sort of monitor you can only estimate the date of ovulation to within two or three days but it gives you a pretty good idea.
Hope this helps a bit, you probably know most of it already but I am a bit long winded 