Am i testing too early?? NEED YOUR HELP?

started the pill on the 7th december and have just started my pill free week.. Had a little mishap with the pill and need to do a pregnancy test..I've just tested this morning with first response and it was negative.. was about 13 days ago.. I know im bn anxious but am just concerned.. what do you think?? THIS IS MY FIRST TIME ON THE BIRTH CONTROL PILL AND HAD BN ON 9-10 DAYS BEFORE