Delayed Period After Birth Control Change: What to Expect

Question
I have been on ortho tri cyclen lo for about 7 months and last month switched to the nuva ring.  When I was on the pill I always started my period on Monday or Tuesday and this month it's Thursday and I haven't gotten it...I was a little weepy last week which is normal...but I don't understand why it's not coming! I'm very paranoid about becoming pregnant.  My boyfriend and I always use a condom also but sometimes we get pretty close before putting it on.  I don't know what kind of effect that has.  I've also been much more active that usual the last 2 weeks and dont' eat very healthily.  Could that have something to do with it? Thank you for your time, it's really appreciated.

Answer
the nuva ring is new, so your best bet is to read the package insert and see what it says about side effects.  any sperm in any amount in the right place can result in pregnancy, so that will always be a concern. you could get a pregnancy test and relieve your mind, too.