Pregnancy scare

Cristina

I have a question. I found out i was pregnant July 18, 2017. Had my first ultrasound July 21, 2017. I am at 6 weeks and 3 days. I was told my due date is March 12, 2018. I am wondering when i conceived. I had sex once with a lover on June 7, 2017 but we used a condom. I have had lots of sex with my husband all month long could it be a possibility that my future child is my lovers? Please help.