Help me

Fa
My cycle is 28 days and periods last for 8 days I had sex on 10,11,13,15,16 today is 16 day of my cycle. After ejaculation I used to keep my legs up for about half an hour and always had sex while he is standing and I am on the edge of bed is it possible will I get Pregnant? What are the chances and when should I do pregnancy test?