Spotting and cramping on Nuvaring

They started the Nuvaring just after a week into my cycle. We waited for about 2.5 weeks till we had unprotected sex. (The doctor and information I found online said to wait 7 days) Now is about the time when I would get my period and the ring is still in. I am getting lots of cramps like my period but with some spotting. I read that these can be early signs of pregnancy so my question is:

Is this a common thing for someone who is using the Nuvaring and missing their first cycle?

Also I have been under tons of stress as of late if that can have a factor in it.