Could I be pregnant?

I had sex with my boyfriend on 14th of January, the condom broke and I took plan b few hours after. I had the normal spotting or the bleeding that comes when you take the drug. My period was due 4 days ago and I still haven’t seen it but I’m having cramps, headaches and fatigue. I’ve done a pregnancy test twice, all negative. Could I be pregnant or it’s just the drug? I bled after taking the drug, doesn’t that mean the drug worked? Please help a sister our. Thank you