I Had My Period On July 15 Y Had Sex

I had my period on july 15 y had sex on july 20 and 5 days later y had blood for a week because i took a next day pill, then an August 3 i had sex and on the 9 i had blood, it was brown and red like a normal period but less, eay less and it lasted for 6-7 days. I’m i pregnant? When is my period coming again?