I guess its possible to ovulate at any time but I would start using the ovulation test strips the day after your period ends and then you should be able to determine when you get your LH surge. That's how I do it and the period and ovulation apps help track it too.
The average women will ovulate 14 days after the first day of her period but it is possible to ovulate at any point in your cycle.
You can't ovulate during a period, it takes up to two weeks after our period to ovulate