Please I need an assurance that I am not pregnant

Hailla

I posted few weeks ago that I am worried if I'm pregnant. My bf wants me to give him a bj so I did it. He kissed me after I performed oral sex on him and then he eats me out. I am so nervous that I might be pregnant. It happened a day before my period and I still had it, it lasted 6 days. I am still waiting for my next period that should come by the end of the month. I need your help to educate me in how pregnancy works, so I don't trigger my anxiety.