Thanks for query,
As she has menstruation
on 10 th of August she is not pregnant.
Your home pregnancy
test also confirms it.
If you want to conceive your intercourse should be fall in fertile period.Fertile period is a period of middle 10 days in regular 30 days cycle.
If your wife's period is delayed or irregular this may not work.
You have to consult a doctor to first make it regular & then if needed she will advise you accordingly.