Ok, this sounds really fishy to me.
From what I understand, when you have a period, it flushes your system of all eggs, plus the lineing that would nourish the eggs, and let them grow. If you do get a period, then, there is no way you can be pregnant (theoretically).
If you did have a period while being pregnant, are you sure that it was the same as your normal periods? For example, was it the same length, same amount of blood, things of that nature? Did it last a day shorter or longer than normal?