False Positive?

I have a 9 month old. Last menstrual cycle date was 1/14. I was on the mini pill. I switched Feb 1st to the Nuvaring. I took the Nuvaring out on the 21st. I was concerned that I hadn't received my monthly. I thought maybe it was my PCOS or I didn't ovulate because of switch birth control. I took a test today 1 at 1:30 and this 2nd at 2:30. Definitely with diluted urine.....Has anyone had a false positive when switching birth control? Does the line appear faster t and darker than the test line if you are far along?