July 23 i was 4 weeks, having 3 partners, can i tell childs dad by concieved date? what would be the concieved date.

Maybe not: If different men are closer than 2 weeks apart (usually a bad idea), and an ultrasound scan wasn't done around 8-11 weeks, it's too hard to guess who the father is. If the woman has irregular periods, it's even harder to pin down when conception happened.

June 21st to June 25: After Sex, the sperm can be alive and active as long as 5 days (in young men), but 2 to 3 days is more common. So, after have sex, the conception date may be that day, or as late as 5 days later.