Sofia Richie is going to be a mom! On Thursday, January 25, the model spilled the exciting news that she and husband Elliot Grainge are expecting their first child together. “I found out very, very early. I was about four weeks pregnant,” the blonde beauty, 25, spilled to Vogue. “I was on a trip to Milan for fashion week, and I was going to the Prada show. I was doing a really quick 24-hour turnaround, and I felt terrible but didn’t think much of it. I thought it was jet lag.” Since Richie was a few days late on her period and was headed to a concert that she knew “was going to be a boozy nigh…