My (M30) wife (F33) lost "our" baby

Well, my wife was 2 months pregnant, when she found out she was pregnant she asked me to talk (It was a few days ago) and told me that halfway through our relationship as a couple and half a year before our marriage she cheated on me with her best friend (with whom she currently has no communication).

Currently we have been married for 8 years and she told me that she wanted to confess it because a child was going to be a change in our lives and that she wanted to start it off right in order to be good parents.

I obviously asked her the most logical question of all, I asked her if that child was really mine, knowing that if she cheated once she could've done it more times, for some reason that made her cry, I was totally angry with her but I didn't want to hurt her, however I didn't want to comfort her either, so I left the room and went to another side of the house to think about my action plan.

Later, I heard her calling me, almost screaming, I approached her and she was in the bathroom bleeding quite a bit down there, we went to the hospital and apparently she had a miscarriage, according to the doctor it was not something forced nor product of some medication, maybe it was an emotional shock (something that already happened to her before)

While she was sitting on her stretcher waiting to be discharged, she asked me what I thought about all this, I just said that maybe it was for the best, words that made her cry again.

I'm not going to lie, I love her, but at the same time I don't trust her anymore, if she could hide a "slip" for almost a decade I don't know what else she could have hidden, maybe this is just the tip of the iceberg, the only thing that haunts me now is to know if that son was mine or not, according to her she has been faithful to me since then and she never spoke or saw any man other than me (which I did not ask her to do) but obviously I also have to question that.

Our relationship was quite good, but now I also have to doubt if every good deed she did for me was out of true love or it was just guilt for cheating on me, anyway I'm already planning a divorce, thank God that son wasn't born because otherwise everything would have been more complicated.

As I said, I love her, but I can't live knowing every action she made for me could be lie, and also I'm not forgiving a cheating.