Could I be pregnant

I had cramps and sore breasts a week before my period was due, which is very abnormal for me. I started spotting last friday (12th) then started bleeding Saturday afternoon (13th). It was unusually light by Sunday night (14th) it stopped. Then monday morning I had spotting again and spotted till wednesday (17th). I'm still having cramps, my breasts are not sore like before, now I just get a pain once in a while. I took pregnancy tests but they said negative, my doctor thought maybe I could have a cyst on my ovaries but I had an ultrasound done and the nurse didnt see anything. Im waiting to hear from the radiologists though. My husband and I are trying to get pregnant, could I be pregnant even though the tests have been negative? The nurse was only looking at the ovaries for cysts on the ultrasound, so I dont know if she would have said anything if there was a fetus.

[mlb1234]

I am sure the nurse would have said something if there was a fetus there and she saw it by ultrasound.  I doubt you are pregnant just from what you said about the bleeding - it just sounds like kind of a weird or drawn out period to me.