Hi - I think I answered your post on the other board, too, but I thought I'd start the chatting here! I think "they" say that you need a LP of at least 12 days to get pregnant, although it is possible to get pregnant with a shorter LP if the embryo has enough time to implant (or implants early).

From what I've ready, a LP from 12-16 days is considered "normal." A LP of less than 10 days is often a problem.

Definitely start charting next month to figure out if/when you are ovulating. If it looks like you have a short LP, there are things you can do to try and lengthen it naturally (like taking B6 or natural progesterone cream) and there are things a doctor can prescribe (such as progesterone pills or suppositories, or sometimes even clomid - depending on the reason for the short LP).

Generally, if you are getting a regular, normal period every month, it is a good sign that you are ovulating. Also, here is a link to a web site with information about recommendations for when to start taking OPKs. http://www.fertilityplus.org/faq/opk.html If you have a long LP, you might need to start earlier than what is recommended. Once you chart and see where you O, that can also help you narrow down which days to use OPKs.

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