I had had four tests! Is it right

Hi

Is it right to write:

In the past last two weeks, I had had four tests.
or
In the past last two weeks, I had four tests.

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Is it right to write :

I received your letters three days ago and I have tried to reply ever since.

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Is it right to say :

Teacher,will we be having class today?


Thanks a lot fot your help.

.
These are right:

In the last two weeks, I had four tests.
In the last two weeks, I have had four tests.
I received your letters three days ago and I have tried to reply ever since.
.

Thanks a lot for your fast replay.:up:
I added this a few seconds ago. Is it wrong?
Teacher,will we be having class today?

No, it's perfectly correct. In the UK, we don't call teachers 'teacher', but the rest sounds natural to me. ;-)