Africans were also used in large numbers for slavery because they were easier to buy. During the beginning of the Atlantic Slave Trade, Africans were willing to sell other Africans as slaves to Europeans because they had their own system of slavery.
You could have sex towards the end of your bleeding and then actually conceive 4 or 5 days later with your early ovulation. The probabilities of getting pregnant while on your period are low, but the possibilities are there. This is not the time to have sex if you are trying to get pregnant.
Yes, you can get pregnant right after your period. You are actually starting to move into your fertility window. On a typical cycle that occurs every 28 to 30 days, the fertility window is usually between Day 11 and Day 21.