How do you know when your pregnant?

Signs of Pregnancy. Lack of menstrual period, breasts tenderness( 1-2 weeks) implantation vaginal spotting ( 6-12 days), increase urinary frequency, fatigue, tiredness, nausea or morning sickness (2-8 weeks), backache, headache, darkening of the areoles ( nipples), food cravings or aversions to food, eventually bluish discoloration of vulva and vagina, increased size of uterus with increased weight.
Missed period. Missing your period, followed by a positive home pregnancy test, would be the first steps to confirming pregnancy.