Hi, I Had Unprotected Sex 14 Days After My Last

Hi,
I had unprotected sex 14 days after my last period( 10th March) but only began taking the everyday pills that particular day.My pharmacist advised that I take the EC pill as a precaution but this was 78 hours later which i did. I swallowed both at once and continued with the everyday pills up to now. My periods were due on the 7th april but have not come up to now. I did 2 home pregnancy tests on 6th and 8th and both came out negative. I want to do another one tomorrow. I hope am not pregnant please advise.