You can download a period tracker app and it will tell you when you're ovulating, me and my boyfriend had sex the day it said i was ovulating and i am now 5 weeks. If you are wanting to get pregnant download that app it's very on point.
Never try before you period due, very low chances hun.
Try Few days after your period finish
Doubtful. :( The egg has most likely no longer viable and your uterus is shedding its lining so even if there was a viable egg, it would have nothing to attach to.