BFN at 5 days after missed period?!?

Lexi
I'm late- about 5 days- and still no sign of spotting. I'm having cramps and my bbs are sore. I've taken multiple tests and they all say negative. Could it still be too early to test? I wanted a blood test but my doc didn't run one when he did general lab work. I've felt run down and the cramps have lasted a couple weeks, all unusual for me. Thoughts?! I'm starting to feel down about this. :(