Confused! Someone help!

So I was on the Nuva Ring .

Keep it in for 3 weeks , take it out and have a period on the fourth week. Put a new one in and repeat .

Well I had a full blown period the 7th-11th of September. Which would mean my ovulation window was the 15-22nd . I hit a blatant positive on September 27th . Wasn’t supposed to take the birth control out until Monday October 3rd. Period usually starts a couple days after that . So I got a positive like 8 days before my missed period. I tested again on the day I would’ve most likely started and it’s DARK. As dark or darker than the control line. HELP .