Low temps after Ovulation

Hello :-)

I am probably being paranoid but when I look at my temps they dont seem to stay high for long after ovulation. I look at other womens charts on fertility friend and most seem to have elevated temps for quite a few days after 'o', only dropping the day or two before AF. Mine seem to drop after about a week and then spend the next 5 or 6 days around the coverline. I have looked it up on the internet but all I can find is that if you have a luteal phase defect then temps drop and AF starts early, which isnt quite my case as AF isnt being brought on by the drop. I have pretty much written off this cycle even though I am only on day 11 as the temps are the same as last month.
Has anyone else had experience of this? This is only my second cycle off BCP (which I have been on this time round for about 18 months), but I have been on and off the pill previously and had no probs regaining normal cycle activity.
http://www.fertilityfriend.com/home/4c342