Short luteal phase and progesterone

[geeup]

I have a short luteal phase - between 10-12 days based on OPKs and temping. I recently had a lap and dye which didn't find any problems so the consultant told me to go away and keep trying for another 3 months after which he'll probably try clomid to boost ovulation. I asked if he could prescribe progesterone to extend my luteal phase while we keep trying (I don't need want to waste more time just dtd which hasn't worked for the past year!) but he said NHS doesn't acknowledge short luteal phase as a problem so he wouldn't prescribe progesterone. Should I go private and try it? Thanks.