To predict the possible ovulation date you need 2 pieces of data: the last menstruation date (the first day your period began) and the regular duration of the menstrual cycle. We can never know exactly how long a menstrual cycle will last but we can assume an average duration if the woman has regular cycles/periods. If we know the cycle’s duration and the date the last period began, we can assume the date of the next expected menstruation (period). A possible ovulation date is defined according to the next expected period date, not according to the date of the last menstruation. The rule says that ovulation happens about 14 days before the next period comes. This means that ovulation will happen 14 days after last period date only if the cycle’s duration is 28 days. If the cycle lasts 21 days, the ovulation will occur 7 days after the first day of the last period (21-14). If the cycle lasts 35 days, the ovulation will occur (35-14) 21 days after the first day of the last period. In your case, it is impossible to predict ovulation date because you didn’t gave me the data about cycle duration.


A pregnancy test becomes positive after implantation, about 8-10 days after conception (fertilization of the egg-cell). In your case, it is possible that you conceived on the 18th of August. because exactly 8 days had passed until pregnancy test became positive on the 25th of August.


I have to potentate that all these dates are predictions and they are not 100% sure!