Am I pregnant ?

I had unprotected intercourse on august 29 then I got my period for 4 days which is accurate on how my period is and it came right on time it was suppose to. And I had no symptoms of other bleeding indicating I was implanting an egg. But usually I smoke weed and I did cocaine and I heard cocaine changes your cycle and body. I’m 11 days late from my period and I dontknow if it’s because I’m stressed about my period not coming or maybe because cocaine changed my cycle. How can I get pregnant if I had my period two days after and it was 4 days long and ovulation wasn’t close to me. Usually my cycle is 25-27 days long. PLSSSS help and don’t judge :/