Can I get a DNA Test done in the doctor's office to find out for sure if my twins are identical?

The doctor told me the girls are identical because they shared the same placenta. But, I've heard that the placentas could have just fused together. They also share the same blood type. I think they are identical, but I want to know for sure, and I was just wondering if you could get that done in a doctor's office? Thanks for ya'lls help.