In short, they were invented a long time ago. The story begins with Babylon and Ancient Egypt, so it is difficult to name the inventors.
One thing is interesting, these are very interesting events. The history of pads is closely related to the history of the tampon scandal, which was followed by the invention of pads. I wrote about both events on my website, you can read (following the sequence):
As mentioned earlier, the idea of pads and tampons is not new, different analogues have existed since ancient times. However, in the current form as we know, most likely appeared after the First World War (information may not be entirely accurate, look at Wikipedia or correct me). Since during combat battles it was required to stop the bleeding of the military, the nurses used bandages, which they then thought of using as a means of feminine hygiene. I don't know the creator and owner of a patent for an invention, but, as you understand, being the creator and owning a patent are not always the same.
During the war, they were created so that they absorb blood from wounds. Well, now (you know from where)
I am writing nonsense for the famous limit of 140.
As far as I know, it all goes back to Ancient Egypt. It was just that it was more ancient then, but now everything has been modernized. In Egypt, young ladies not only invented pads, but also tampons. The parchment helped in both cases