I had sex for the first time on the 20th

Patient: I had sex for the first time on the 20th of this month. However he ejaculated inside of me, because of this I’ve been worrying non stop about being pregnant. So on Wednesday (exactly one week later) I took 2 pregnancy test, few hours apart. And both said negative. Is there any chance my period could be delayed its approximately 2-3 days late

Doctor: