Irregular Period After Ortho Evra Discontinuation: Pregnancy Concerns?

Question
27 - no kids.  My last period began 10/21.  I've been using Ortho Evra and last month, my period, which usually takes 3 days to come on after taking the third patch off took 5 days and then lasted for 6-7 days ending on the 28th.  I decided not to go back on the patch but had sex on 11/4.  I have read that it takes 2-3 months for your cycle to become regular after discontinuing the patch but am still concerned about pregnancy.  Is there a strong chance that I could become pregnant so soon after discontinuing the patch?

Answer
If you did not start a new patch after you got your period on October 21, you probably ovulated around November 3 and could have conceived if you had unprotected sex on November 2,3,4, or 5. If you do not get your period on November 17, wait an additional week and take a pregnancy test. By the way, the period you had that was three days late and lasted 6-7 days is within normal limits. The patch is 99.9% effective in preventing pregnancy.