it could be possible that you are. however you should go see your dr and ask for a blood test and/or an ultrasound. although the home tests are fairly accurate i found out i was pregnant after a blood test was positive and i had taken 3 home tests all of which were "negative". go see your dr its the only for sure way to know.
i missed last month period and i havnt started yet i took home test and they say no and my belly is bigger am i pregnant. i done this with my other one and i was on birth control