Nuvaring and pregnancy

So this my third month on Nuvaring last month when I took it out I had no period, I did take a test just to check and came up with no lines! My luck! Anyways I went on with my third ring but during this month my breast have gotten fuller and I have been a little tired but my main issues is has this happen to anyone? I know breast changes can happen on Nuvaring but no period? Just looking to hear from others who have had these issues while on Nuvaring, were you pregnant or just side effects from the the birth control