I stopped taking my birth control(the pill) in March of this year. Ever since then, my period has been regular. I never missed a period and it always came on the day it was expected to come. But this month, I'm 6 days late. I've experienced NO sign of my period, which is unusual. I've been kind of moody, I don't have an appetite, and certain smells make me nauseous. I took a home pregnancy test but it was negative. Is there ANY chance that I could still be pregnant? How long should I wait to take another test or see the doctor?