Hi there,
I just saw this and wanted to add my piece. I know that I conceived once following sex on day 7. I know this because my partner had a bad back which prevented us trying again that month.
Unfortunately, it turned out to be an ectopic pregnancy. This was due to damage of my tube and was not connected to the time of conception.
I think women are mostly likely to conceive mid cycle. However, stress / illness can all alter when it happens even for those of us with regular cycles.
Love NS XXX