When i got pregnant ?

So on February 28 we had sex and he came inside me (it was non fertile window days) obviously because next day it was my period time to show up and it did show up normally

Then on March 12 we had sex and he came inside me i am sure it was my ovulation day

After exactly 6 days of March 12 i did a test and it came positive

Is it normal to get bfp after just 6 days of intercourse? Or it was pregnancy from Feb 28?