missing a period does not mean you are necessarily mean you are pregnant but if you are trying to get pregnant or not using any form of contraception you are likely to eventually get pregnant (assuming your partner is fertile). there can be dozens of reasons for delayed or missed periods so it is wise to see your woman's health care professional for a proper examination and a more sensitive pregnancy test if your cycle does not self-correct and especially if you are starting to show other signs and symptoms of pregnancy.
i had sex on 10/12/2015 my last period begun on 10/2 but i tested for 3 times at home all the results were negative. its now november 2nd i haven't seen my periods