I get a lot of bak pains and pain on my vagina like knifes stabbing me
I don't know if this is your problem too, but I had bad kidneys in my 3rd trimester of pregnancy, dark color urine is usually blood in urine, but with the green poop, thinking if no back pain is involved, it could be the dye in your prenatal vitamins, hopefully that is all it is.
Concentrated urine means you are dehydrated. Make sure you're drinking adequate water. If you are taking a vitamins with iron and eating dark leafy vegetables then I would not worry about the color of your poop. Follow-up with your doctor at your next prenatal visit. Take care!