I found a great website that takes your cycle length and LP into consideration. If you google Pregnancy Expected Due Date Calculator and got to teh site that is called - hpathy - blah blah... you enter the First day of last period, your cycle length and LP length, it will tell you the EDD, the date of likely conception, and how many weeks you are!!!
That's cool that site. But my cycles have been very different since coming off the pill. I'll have to go back to my FF chart and see what it said my "average" cycle was.

So maybe my due date is not 15 July...