pregnant?

So my boyfriend and I had sex about 3 weeks ago and we didn't know if he pulled out in time, and the condom was only on the tip. But now my period is 5 days late and I have sore breast, headaches, back pain, I'm always hungry. But the pregnancy test came back clearly negative. I'm not sure if I should use a different test or just assume I'm not pregnant. I used the equate test, not sure of its reliability, but they're clearly negative.