How soon after intercourse can you show symptoms of pregnancy?

Some people say that they felt pg within days, but it usually takes 6-10 days for implantation and HcG (the pg hormone) is not created until after implantation. this is the hormone that is responsible for symptoms like nausea, vomiting, constipation, gas, etc. Progesterone is present in all women for approximately two weeks after ovulation, but for pregnant women it remains high, and for menstruating women, it falls. Progesterone causes alot of symptoms common during pg, but can also cause those symptoms for women during the two weeks after Oing and before her period. Many women say that they felt pg very early, but what they were probably feeling was the effects of the progesterone that they would have felt otherwise, but only noticed, or remembered because they ended up pg and the symptoms continued and became more prominent.