How to change date

Danielle • Married to a wonderful man. 1 miscarriage and hoping for our rainbow baby soon
Today I'll be talking on of the pregnacy test that can tell you how many weeks you are. And when I find out how can I just my dates because right now i don't think it's right like right now it has me as still just having an egg. I took ovulation test and I think I conceived on June 12th