First Of All I Have My Tubes Tide Almost Trn

First of all I have my tubes tide almost trn years ago. i been gaining weight rapidly and my stomach sticks out like a pregnancy looks. I am having movement on my upper abdomend constant, come and goes. I still get myperiod monthly. I was at the ER and took a pregnanct test and ir was Negative. I also took a blood test and my results were all normal, no infection. is it possible I can be pregnant? I haven't had a ultrasound to check if I am.