After intercourse what in minimum time you can know that a girl is going to be pregnant?

After intercourse, it typically takes about 6 to 12 days for a fertilized egg to implant in the uterus. Pregnancy tests can usually detect pregnancy about a week after implantation, which means you might be able to confirm a potential pregnancy roughly 1 to 2 weeks after intercourse. However, for the most accurate results, it's recommended to wait until after a missed period, which is usually about 2 weeks after implantation.