I have every sign😭 I need help

I have not had my period in 2 1/2 months. Last month I was throwing up almost every day at all times. I'm cramping, my stomach muscles are tender, along with my breasts. I'm a size 5 and I can't button my pants for the last week because I have a random pot belly pocking out. I have not been spotting or anything. My last pregnancy I was diagnosed with ulcerative colitis. I have been suffering miner flairups the past 2 weeks. I have taken 4 pregnacy tests my 4th as we speak all 3 came up NEGATIVE. . . WHAT DOSE THAT MEEN😭😭😭 any one?