Odd bleeding and period ?

OK, here's the situation. My LMP was 7/4/09. My period comes like clock-work on the 4th every month. The only time it's off are the months of Feb. and maybe Mar., I guess because Feb. is a short month. Anyway, I started what I thought my period on 7/27/09- just spotting here and there- never got any heavier. My period usually starts light but very shortly, I began to have cramps and a heavier flow. So the spotting lasted off and on til 8/1/09, then at this time it's a little heavier flow-red in color- still no cramps, bloatness, or any "period" symptoms. I do have a mild headache occasionally, very mild I think cramps on the left or right of my pelvic area, very tender nipples and breast, and occasional low back pain. Sometimes my breasts are so sore, it seems it radiates to my upper back- weird. So today, 8/3/09- the bleeding is still not like my normal period flow. It's red, but still no cramps, irritability, bloatness. I am gassy, feels like the gas just sit and I can't expel it (sorry so graphic). Apart of me says I'm pregnant, but with the bleeding, I know it's not possible. I have a doctor's appt. Friday. I wish I was pregnant, but I also want to know what in the world is going on!!!! I want a child so bad!!!! My husband feels the same. By the way, my period usually last only 4-4.5 days. It has never come this early nor has stayed on this long!!! Does anyone else feel my pain??? I took a HPT Sat, but was negative.