I'm confused

I've always thought my cycle was 28 day long. But the average for the last 4 months have been 27 (Oct 26 days, Nov 26 days, Dec 27 days and Jan 28 days. Which totals to 107 and average 26.75. So I rounded it up to 27). I took an ovulation test on Fri Jan 30th thinking it would be positive beings that Glow said my most high fertile day was Sat Jan 31st. But it was negative. So I'm so confused on which day I ovulate. Maybe I took the test too late. But shouldn't it had still showed positive for LH surge? I took the test on Fri was supposed to ovulate on Sat. Should I had took it Thurs instead? I'm so nervous because I was on birth control since I was about 16-17. I'll be 30 this year. I've been birth control free for a year and 5 months now. My gyno keep saying nothing is wrong with me but she's only speaking on pelvic and vaginal exams. Maybe I need a thorough fertility exam. I'm praying to get pregnant this year. Hopefully in the next 6 months. I'm keeping up with my cycle and having sex 1 to 3 days prior to ovulation and on the actual ovulation day. Is there any suggestions or help that someone to give me? I would greatly appreciate it