sucking it in!!!😓

Sara • FTM • DD Nov. 24 but born Nov.19 • Happily Taken❤️
I was taught since I was younger to always suck my stomach in. I was never fat or anything I was always slim so that bad hbit got stuck with me till now. I'm 29 years old and was taught at about 13years old. Now I'm pregnant at 8weeks 2 days and I suck it in and then when I notice I'm doing so I release my stomach. Is that bad for the baby???? 
I'm trying to stop this habit because I don't want anything to happen to my baby. It's just hard when you've been doing it for years.😓