Does no period mean you are pregnant? On the ring

Sarah

I just started nuvaring and it’s the first cycle that I am taking the nuvaring out. I followed all the instructions in the booklets and waited 8 days after having it in before having sex. After 21 days I have taken out the ring to have my period withdrawal bleeding and 5 days later I still don’t have Any blood. Could I be pregnant? I’m so scared. How do you know each month if the ring worked if you don’t get a period?