how accurate would this test be?

for the month of october i started my birth control 2 weeks late. my period in september came during the 20's. so 2 weeks into my pack on oct 22 i started bleeding. i wasn't sure if this was my period or my body messed up from the pills i asked a doctor online and she said it was most likely my period which makes sense since i had my period in september in the 20's. so with that being said i am guessing my period was supposed to come in the 20's this month. i am not on birth control because i stopped because i wasn't sure if that was it or not. so...

I had sex 1 week before my period was due.(Nov 15).  19 days after unprotected sex and 12 days after the first day of my missed period i took the first response pregnancy test and it was negative. I have no pregnancy symptoms. I have been extremely stressed so is it most likely stress delaying my period?

[spade22]

Most HPT's will detect pregnancy about 2 weeks after conception.  Since you took a good, sensitive, test 19 days after unprotected sex you probably are not pregnant (if you took the test correctly and used first morning urine) but its still possible.  You can retest in a week.