Magnesia. Its safe to take but take it a day your home all day cause you'll spend it in the bathroom lol
U also need to drank tons of water
Have a look at this Digestic by Mimonis which was used also by my wife when she got constipated. Even if she was pregnant at that time we still used it because it is safe and purely organic.
I used a gentle women's laxative while pregnant with my daughter. I think dulcolax. O took it before bed and woke up in the middle of the night. It did give me stomach cramps but it helped me go. I would take it in the morning and wouldn't use it regularly.