When should I expect my period?

Hey guys.

I was royally stupid this month. I waited until two weeks after my
period to begin my birth control, which means there's a good chance I
could be pregnant this month.

What would be an appropriate time to test for pregnancy? I've
technically already missed my period (minus a little spotting the
other day), but my test was negative. I'm guessing though that by
starting my Nuvaring two weeks late, that it's going to make my period
two weeks late as well??

Thanks for help.