2 months No cycle

I was just in a toxic relationship and when we started having sex my cycles started to become irregular. We were always having unprotected sex and trying to conceive. It’s been 8 months now and it’s been stressful. My last cycle was November 16th, 2020. I still don’t have a cycle. Could it be stress? I have gained some weight. But I do have morning sickness and pregnancy symptoms. I went to the emergency room because my doctors office isn’t taking anyone else until February. They gave me a test and said I am negative for pregnancy . I’m so confused. I’ve stressed a lot with both kids and still had a positive test. I have anxiety so idk what’s going on with my body right now. Please give me any type of explanation or if you went through anything similar.