How long after having your baby did you developed a workout routine

I’m currently 24 weeks now so I still have quite some time before that happens but lately I’ve really gotten feed up with how I’ve treated my body over these last few years. I noticed stretch marks on my arms and that alone convinced me I had to be serious about my eating habits and workout routine after baby is born. I know you’re usually clear to start at 6 weeks post but obviously it will be challenging since most of my time will now be dedicated to my baby and work. How’d you ladies do it ?