Hi.. Pregnancy is considered if you find a sudden irregularity in your menstrual period, nausea, vomiting, enlargement or sore breast, headache, mood swings, food cravings and so on.. These symptoms are morelikely due to pregnancy if you have had unprotected sexual intercourse during the fertile period of menstrual cycles (during the time of ovulation). Confirmation of this by getting the pregnancy test (either urine pregnancy test or blood HCG level) or by an ultrasound examination..