Pregnant after period

My period ended on the 1st and we had sex on the 2nd. My fertile days start today & yesterday when I went to the toilet and wiped twice I had brown discharge. I haven’t had any since then. Only time I have ever had this was when I found out I was pregnant with my first but it was after me ovulating. This is so out of the norm for my cycle. Is it possible to conceive a day after your period?