im 21 yrs old girl i have a 3yr old and a two yr old i got on the implanon after my son i got off march 12, 2012 i started the pill for a week then stopped i had my period on april 4,2012 then i had unpretected sex on april 15,2012 i have had abdomenial pains, headaches, back pains and sick to my stomach for 6 days can i be pregnant can anyone help