It sounds very likely. There are quite a few of us who either know for sure or suspect that DES was used by our mothers during pregnancy in that era. I am one of those. Unfortunately, my mother is no longer alive, so I can't ask her.
It is comforting to have an explanation, even though the explanation itself makes no material difference in our lives now. The comfort, I think, comes from knowing that there was a physical cause, and that this was not some weird choice we made.
For me, I have filed this information under "interesting trivia", and don't think about it any more.