I am worried I overdid it

I took 120mg, three pills that were 40mg each. I heard that 80mg was the lowest dose, so I figured it would be fine to take 120mg. I am wondering if I am really screwing myself up. Hopefully not. It could just be a wonky period, I have had them before. I was just wondering if it was more than a coincidence that the bleeding was long this time and the soy was involved.