Thank you for reaching out to the EmpowHER community and sharing your question. It is very unlikely that you are pregnant since you took the ECP right away and it was a week before your fertile time.
There's always a risk, but I am sure that you will be just fine. One of the most common side effects of the ECP is to delay your period and change your cycle. So don't be alarmed if your next cycle is irregular.
Here's an article from the EmpowHER community with some more helpful information
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