Late period

I had sex March 13th... But it really wasn't sex he only had the tip in. And he didn't even have it in for 5 minutes. He didn't cum inside me, but when he got home he said he found some cum in his underwear. Now I'm freaking out because my period is 3 days late and I have all the symptoms, but it just won't happen!! Someone please reassure me that I'm not pregnant!!😳😬