Confused

sierra • Mother of a 10year old(rainbow), and a 5 year old (rainbow), and an angel baby girl❤ (lost my pot of gold, furthest loss for me), Rainbow babygirl due in May.
Hi :) I just started using the ovulation kits with the pregnancy tests from earlypregnancytests.com and yesterday I was supposed to start but did not I took a pg test negative so being curious I took an ovulation test. The test had two dark lines matching meaning surge of ovulation right? I thought that meant you have 24-36 hours of ovulation but when I took a second ovulation test this morning the second line was lighter? Does that mean I missed my window? And is it normal to ovulate when your expecting your period?