My wedding is 15 months out, is it to early for me to start planning? Can anyone give me an example of a planning timeline?

My fiance and I have been together for 3 years. We just got engaged a month ago. We keep our relationship pretty private and away from the majority of our messy co workers. We are 32 and 33 years old. Hes older. In the past he has told 1 of his guy friends at our job that he has seen me naked although we have not had sex yet. (We are practicing abstinence until marriage.) I was angry but he acted like it wasnt a big deal. Just today my co worker who knows about us asked me if we are going to move in together when I buy a house in a few months. I told her no because we didn t plan on getting married that fast and I dont believe in shacking up or living together before marriage. I told my fiance about our convo and he got extremely angry saying that I told her our business. He is so mad that he is not answering my call and I actually think he blocked me. On a normal daily basis we are really sweet to each other and get along like best friends. He calls me babe and I call him honey.