What could it be, getting worried?

Yesterday I went to the ER to figure out why I am having so much pressure, they did a blood test and to check to see if I had a UTI, all the results came back negative as I thought they would. I'm 11 days late negative PG test and feeling a lot of pressure. I called my doctor to get an appointment and they still haven't called back. I'm getting worried, I feel it in my uterus when I bend over and what not, I feel pusling at times too. my heart seems to be pumping more I noticed too, the doctor in rhe ER said my heart beat was at 108 just sitting there. I'm getting scared...is this pregnancy or something else?