Nuvaring- pregnancies while using?

I have been taking nuvaring for about 2 years, I had sex my fertile week every day (the 2nd thru the 6th) and on the 5th, I had my ring out during sex and accidently left it out overnight. This week I have had cramps, bloating, slight nausea, Been crying randomly, VERY tired, and today I had some brownish spotting for about 3-5 hrs then it stopped. I am supposed to take out my ring in 5 days, meaning my period would start 1 week from today. Reading online I saw implantation bleeding would happen around this time for me. 
Could I be pregnant? 
Anyone else gotten pregnant while on nuvaring? Please help! 😬
*Side note, a few months back I got a positive pregnancy test while using nuvaring. I suspect I had a chemical pregnancy. Could this mean I'm more likely to get pregnant again on nuvaring?