I've been using nuvaringI'm on my 2nd ringI put it in @10 & had unprocted sex @5could I be pregnant?

Once you have started on it, you are protected even during the week you have none in.

You are fine. You should use back up protection the first week but after that you are protected, even during the week there is no ring in, as long as you stick to your schedule and the ring is not left out too long and is changed on time. Sometimes women will spot a bit if they have sex right after their period stops. It is likely that the uterine contractions during orgasm loosened a little unshed lining that remained in the uterus and that lead to the spotting.