started taking an older prescription i had of amoxicillan and i didnt know it lowered the effectiveness (the writing on the bottle faded except the amoxicillan part & i no longer had the phamplet) until my mom who is a rn informed me i could've conceived. my lmp was 8/29/09 and i was suppose to start my period 9/26/09 and start my new pill pack 9/27/09. i took a test 10/1/09 and it was negative... could this be i tested to early? i still have no period.