How you tell your husband you’re pregnant depends on what you expect his reaction will be. If you expect he will be thrilled and excited, make it a big surprise. You could buy him a baby onesie with a saying on it like “I Love Daddy”. You could buy him a box of bubble gum cigars (or real cigars) to hand out to his friends and co-workers.
If you expect he will be anxious or worried when you tell him you’re pregnant, pick a time when you know you will have enough time to talk without being interrupted and when you don’t have anything else important to do. This will allow you to have a serious conversation