Could I be pregnant? Took test today

The last day of my period was the 4 of February I had sex on the 8 (the condom broke) was unable to buy plan B...I have been taking my birth control everyday but it's been only 2 months on this new birth control so my period is a little irregular. According to Glow my period is due on the 28 so I took one of the first response tests that tell you 6 days before your missed period and it came up negative. Does that mean I am not pregnant?