Babydust,
Your symptoms very strongly suggest low progesterone. I know 2 other ladies on here with this problem and we all had short lutheal phases, spotting, and light periods. The progesterone cream is not very strong, I was prescribed progesterone pessaries at 400mg twice a day. My doctor was very sceptical about treatment, I don't think it is widely accepted yet. I know it isn't cheap but if you are willing to part with about £100 you could have a consultation with a fertility clinic. In total I spent £200 on consultation and tests before they prescribed me with this treatment. The first month I took it we missed ov as it surprised us by happening 4 days early, but the following month we bonked for England and I fell pregnant. The other thing I will say is that no all people have a permanently low progesterone level. Mine was perfect on some days and very low on others. One test came back 2.5 and the second came back 63.9 (perfect) because of my fluctuating temps and because I was seeing a fertility specialist she agreed it was worth a try on the pessaries anyway. My doctor would never have conceded to this.
What I'm trying to get at is that if you can bare to spend the money, you will be taken more seriously at a fertility clinic, I really think you may be right about the low progesterone and wish you luck. The good news is that once diagnosed it is very easy to fall pregnant. I wish you all the best and please pm me if you want to chat or rant.
Becs
P.S NW1, same applies. I'm not sure what your symptoms are but give me a shout if you want to chat. i was gutted when we lost you from first tri xxx