Could i be pregnant

I was due for a depo shot in november 2005. i didnt go get the shot because i wasnt having sex. i started having regular cycles in january 2006 and i have had it every 28 days exact i had sex may 3, i was 6 days late in may and this month i was 3 days late.i was feeling lightheaded and a queasy but i havent in a couple of days. Could i be pregnant?

You can be pregnant ANYTIME you have unprotected sex. It would be a good idea to take a early pregnancy test.