Sorry to hear you are having trouble with TTC#2, it can be such a stressful thing.

Do you know what units your progesterone was measured in? mIU or ng/mol I think are the two different ones used.

If you think you have a LPD (luteal phase defect, a short post-O phase of your cycle, or spotting) then you can try and supplement that with herbs like Vitex and Maca root, or ask your gynae / FS for clomid which also does wonders for LPD.

It is great news that you have a temp spike each cycle and the US was clear, let's hope the sperm and egg meet for you very soon .