Could it be a urinary tract infection, and that you have a little blood mixed in with your urine, making it pinkish? I've heard UTIs are pretty common during pregnancy. Do you have any other symptoms that might suggest this? Like an urge to pee, but when you go, nothing or very little comes out? Or do you have any burning while urinating?
The only other thing I can think of is that it's related to something you are eating or drinking. I know my prenatal vitamins seem to make my urine a lot more yellow that normal.
If your urine is pink you should go to see a doctor. But it could be many things. However personally I would go to the ER or whoever could see me right away. I personally have never experienced this. So I hope that you and your baby are ok.... Best of luck