Is there any reliable method of calculating the time one was conceived?

[Excerpt from TT: 2001-11-15]

[Elf] You have said that the astrological chart of the moment of conception is more telling than the birth chart. Is there any reliable method of calculating the time one was conceived?

[Michael_Entity] By observing the primary physical manifestation of the Body Type, you will know the planet at the Midheaven at birth. This can lend some clarity to determining the rest of the chart. If a Body is primarily Martial, this means Mars was near the mid-heaven, for instance. This can act as an extrapolation for the rest of the chart. Knowing the general time it took for the pregnancy, of course, will lend to that calculation.