I Think U Might Be 25 -30 Weeks Pregnant I

I think u might be 25 -30 weeks pregnant I had my tubes tied about 7 years ago. in aug 2015 I got a weird period and have been feeling off since then and even my period continues to be weird. I have a very round and hard stomach I have been to the doctors several times they did blood work and an ultra sound but didn't find anything but I don't think they are looking for a baby since my tubes are tied. all urine tests come back negative. as of the last month I have been feeling what I think is movement but im not sure. i feel like im going crazy and don't want to go back to doctor because they think im crazy to