What Causes Sickness After Having Unprotected Sex During Fertile Days?

me and my partner have been trying for a baby for about 9 months, we have unprotected sex on and around my fertile date, i have a one night stand about 4 days after my ovulation date, it only lasted about a minute before i stopped it and he didnt orgasm, i am now four days late and worried sickas a baby is what we have been longing for, we have been together 5 years and engaged