Hi K.,
Are you sure they are your kidneys that hurt? Do you have history of bad kidney's? Or have you been diagnosed with kidney infections?
If you can find an unsweetened cranberry juice that you can drink plenty of. Drinking to much sweetened juice can cause you diabetes. Pregnant or not.
Home remedy: What you can do is buy some corn in the cobs and boil the cornsilk that's inside the corn husks. You can boil the cornsilk in plenty of water and drink it all day long. You will be urinating like crazy but you will be cleansing your kidneys out. Or if you know who owns a chinese plum tree (gives orange/yellow small balls of fruit and it has a bone in the inside). You can snip 2 med sized leaves and boil them in water and you can do the same drink it all day like water. And this too is good to cleans your kidney's.
Of coarse, I do highly recommend you getting checked out by your doctor because what if it's not your kidneys. Or if they are maybe you can get treated before you get an infection. The kidney's are very important and if you sense something is not right w/your kidneys you need to get treated because then they can go caput and then you will have to start on dialysis.
Well, hope you get better. And I hope these 2 remedies help you and give you some relief.
I knew of another home remedies for the kidney's but I can't remember right now but I will see if I can find it