kerala sorry didn't see your post! I've read a small minority of people can ovulate straight after AF. Some people think they don't ovulate at all and then dtd early on in the cycle and get their bfp.
shary dtd eod seems like a good plan to catch the egg, it's worth a go! I found a really useful resource about days to dtd on SPEM when you have longer cycles, I'll try dig it out.
Welcome Judy. Don't be too put off by the 'guidelines'. My GP was very much reluctant until I got my day 21 bloods back. You've already started the ball rolling getting them at that is the first step before they can even think of referring. Do you have any children or are you ttc #1? If you are TTC #1 then guidelines say a year and I'm sure it's fasttracked if over 36 due to risk factors.
Your day 21 bloods are looking for progesterone levels. 21 is the optimum date for most regulate people at this is a week before AF and progesterone levels should be at a peak, they then start to drop in AF is coming of continue elevated if you have got your bfp. The issue with us short luteal phase lot is our progeaterone levels drop too soon and AF appears early or as was in my case progesterone levels were so low that I was supposedly not ovualating at all. When are your tests? The higher the level the better.
However, as I said this test is for people with regular 28 day cycles so if you ovulate later (your cycle is similar to how mine was) it may not sure your progesterone levels peaking. My level was 1, I was told that this meant there was no chance I've ovulated this cycle and was referred to a specialist as the level couldn't get much lower! Then I got my BFP that month!
The other tests are for LH as this should be compared with the progesterone levels.
To increase luteal length and the month I got my bfp I tried:
Mega B complex (from Holland and Barrett) which contains folic acid - B complex is supposed to help lengthen
Vitamin c - 500mg (lots of studies done on this)
Pre-seed
DH on conception vitamins
Get the bloods back and go from there. Has your partner been see their gp too? It was recommended by my gp that DH did to rule that side of things out.