i have been off my birth control for four months and not had a period in three. i have taken three at home pregnancy tests all came out negative. i also went to the doctor and they gave me one and it was a cheap test that you get at the dollar tree. i asked why wouldnt i have a period if i'm not pregnant when me and my husband use unprotected sex all the time? she simply replied that i was too skinny..even though i weigh more now than i did when i first got a period..could i be pregnant and it just not show up?