I'm 18 days late my last period was July 9th I took 2 pregnancy test and both were negative my periods are often irregular but recently after being taken off birth control (orth evra) they have been normal. I am sexually active and the past few days I've felt very tired and get dizzy and nauseous at times. Could I be pregnant?

There is a very good probability that you may be pregnant but you should ask your doctor anyway