Am I pregnant?

Nie

I need help :((

I supposed to get my period on July 18

And my last period was on June 18 (usually last for 6 days). My period is always on time. I had unprotected sex from the 10-17july and now I’m late since the 18 (13days)😭. My HPT are negative. I don’t know if I’m pregnant or not, I’m only 18 so I don’t think I have any illness. My bf and I want to have a baby. Please help😖