Could I Be Pregnant?

Hi,
My last normal period was 9/5/07. My cycles are always 27 to 28 days and I am very regular. I had intercourse the weekend of 9/15/07. The following week I experienced cramping in my lower belly. It was weird, but I figured it was pre-period cramping. On 9/28/07 I started spotting and I figured my period started, eventhough it was very light, only lasted two days and I had barely any cramping. I normally have two days of cramping and my cramps will wake me for a dead sleep they are so bad. Once the bleeding stopped, I started to have your typical pregnancy symptoms, especially the nausea, bloating and I could smell everything under the sun. My bb's started to feel heavy and sore. My temperature has also been higher than normal. On 10/12/07, I experienced major cramping mainly in my lower belly and it was very bloated. This lasted about three days. My temp jumped another 7 to 8 degrees, my nipples are getting larger and I am having more frequent headaches. I have taken four HPT's and all have been negative. Could I be pregnant but it is still too early to test? If I am not, there is seriously something wrong with me, cause I just feel "off." I do have a doctor's appointment for the blood test on 10/22/07. Any insight would be great. Thanks.