Concernd about worming medicine and pregnancy

I have taken in a cat about a month and a half ago because a lady was giving her away for free to a good home. I now know that the cat is pregnant, but when I went to pick her up from the lady she told me that the cat had worms, so when I got her I gave her worm medicine. Now I worry because i gave it to her but I didnt know she was pregnant at the time. So my question is.........could the worming medicine harm her or her babies?