Ovulation cycle timing question

Linsey • 🌷•TTC since 2017•🌷 blocked tube & low egg reserve🤘🥴

2 cycles ago my cycle lasted 29 days. My last cycle only lasted 27- My period just started today. I started taking ovulation test strips daily around the 10th day of my cycle. I didnt get a positive strip until the 19th day which would mean I ovulated on day 20. But that seems really late doesnt it? For a 27 day cycle? We had sex on the 18th day. I'm trying to get this timing down but day 20 seems super late to me???? Help plz lol