Scared of losing my boobs

I’m gonna start working out towards the end of this year when I start getting paid. I’m afraid when I start working out I will lose my boobs. They are a decent size maybe in the late Bs early Cs. (Haven’t been measured but my boobs have grown) I’m about 5’ and I weigh somewhere around 113 and I want to gain lean muscle just over all be more fit and more happy with my body. I already know I’m going to work out. But if I lose my boobs I don’t wanna have to get a boob job. Because I don’t want to be flat chested, that’s just a personal preference. I need advice please