Eightish days late, negative test, could it be something else?

[majo]

I'm 24 yrs old, married, we only use condoms as protection. I was on bc but have been off for six months b/c I wanted to stop putting hormones in my body. My periods have been regular (1-2 days off)...My last period started October 2nd and it is now November 10th and I was supposed to have started oct. 31 or nov 1...so, I took a preggo test this morning and it was negative...i have been nauseous throughout the day (not wake up nauseous) for a couple of weeks now - I have off and on mild headaches, i have an increase in discharge (which makes me think I'm going to start), other than that I don't think I have any other symptoms...I do think that my breast feel tougher (weird)...anyway...I'm a little scared that I may be pregnant even though the test said no - we are not actually trying to have a child right now...should I wait to see if I miss my period in Dec. - that' a long ways away! Should I take another test in a few days? Oh, a couple of days ago I did have diarrhea but now I am feeling constipated when I "go" and my muscles seems to even feel weak...like I don't even want to work out - which i normally enjoy...i just want to sleep (which I can not do)...thoughts, ideas, suggestions?