Laws of Purity

Hello Rabbi
I wanted to ask. My wife had a miscarriage early in her pregnancy two and a half weeks ago. We were told that we had to wait two weeks to make sure it was a girl. And after that, we waited two weeks even though the bleeding had stopped eight days after the miscarriage. From a check in the Shulchan Aruch, it was clarified to me that we can start counting the number of clean days within two weeks. The problem is that my wife did not do a purity test when the bleeding stopped, but at the end of the two weeks. My question is whether we can trust that she saw that the bleeding had stopped after eight days even though there was no purity test or there is no such thing.
B. What is the meaning of brown spots? And what is their meaning when they tend to be reddish? And if this is forbidden, what is the ruling when most of the spot is brown and does not tend to be red and only in a small part, less than a grain, does it tend to be red.
PS I would love to receive an answer from the rabbi rather than the request because I have already seen it in the scriptures and I would like to hear the rabbi’s personal opinion. Many thanks in advance and have a good week.