Feeling dizzy/nauseous lately!!!

I've been charting my cycles here for a little while now and according to the chart my abg.cycle is between 31-36 days long...soooo according to that I "should" get AF today but no signs yet LMP was Feb 16 (I can normally tell, I would get mild back aches and mild cramps, but nope, nothing yet)...I have been feeling a little nauseous (?sp) lately and slight dizzy spells (almost as if I want to throw up, but don't) but that's it...I don't typically get your regular "period" symptoms, and having had 2 kids already nothing signals pregnancy flags...so i'm waiting out the week to see what happens...BTW not actively trying and not on any birth control either (besides the fact that my husband swears that he has perfect timing as far as the rhythm method...but us women know otherwise LOL)