LH surge after period

How soon after your period ends do you get the LH surge?

I’ve heard an LH surge happens before and after a period, but i haven’t been able to find anything about how soon after that happens.

I got my first ever positive ovulation test 3 days after my period ended. I have short cycles, do you think it was just a post period surge or I ovulated?

I don’t track BBT to check that way😕