Can you get pregnant on your period?

So I had my period March 2-6th and had sex on the 28th of fen March 2, 3, and 4th. I've been pretty tired lately and my tits hurt but I took a prego test and got negative. Well my period is due today. And hasn't come yet. I also ate a hamburger today and it was delicious which doesn't sound like a big deal until I tell you I don't like burgers lol is it piasible even though I got a negative like 2-3 days ago. I feel like if I got pregnant on my period it would of been positive by now. Opinions?