I don't know if anyone else has heard this, but in Natural Fertility (by Francesca Naish) it says that you can have a spontaneous ovulation when the moon is at the same place in its cycle as it was when you were born (natal angle). This is even if you have already ovulated or during your period. Has anyone else heard of this theory?
I think most Astrologer's who are remotely interested in how cycles affect physiology would know about this theory.

There are essentially two 'fertile' periods, and it is two weeks after bleed, and also dependent on moon's natal angle. If you don't know what that is, consult an astrologer or get a chart drawn up.

There are of course a number of other mitigating factors, not the least of which is how healthy and tuned-up your body is. The healthier you are, the easier it is to get pregnant.

Also the happier you are - don't dismiss the power of oxytocin and endorphins in relation to fertility - they're not just used for labouring.

Now of course if you have a Chinese Medicine practitioner who is also an Astrologer, then you're laughing......