Negative blood test, still feel pregnant!

I don't know if it's just me really wanting to not believe its negative, but I really feel pregnant. Blood test for hcg was <1 , but I have heartburn and acne (which NEVER happens to me), nausea every night, headaches, and cravings for sweets(again, out of the ordinary). So I guess what I'm asking here is, have any of you ended up pregnant but had a negative blood test result? Im also 3 days late on my period.