Nexplanon

Joo
I have a question about nexplanon.
I got nexplanon implant on October 5th and had sex with my bf couple of days before Veterans Day. And I was supposed to start my period on November 15th... And I haven't started on it yet... I'm freaking out if I'm pregnant or not... On glow, i pot my period late, and it predicts that I would start on the 20th... So should I wait till that day? 
Was it too early to have sex?? What should I do? I'm trying not to freak out about it. I can't get pregnant right now. It's not the right timing and I don't want children at all.
Please help!