I am almost positive my household had it (as well as my family/extended household) in December-February. Have you seen the new "pediatric syndrome" article going around? Not all kids who display these symptoms are positive for Covid, but my son (he was about 18 months at the time) ended up hospitalized in January. He was super sick over Christmas, started to get better by new years, and then two weeks later began throwing up CONSTANTLY, and wouldn't eat or drink anything. He ended up passing out and had what looked almost like a seizure, and the hospital/ambulance called it "respiratory arrest". They tested him for both flu/RSV and both came back negative. They ended up saying it was just caused by severe dehydration and kept him hooked up to a saline IV for three days (he continued to throw up for about a week). I passed the article on to 5 or 6 people and didn't say anything about what I thought, and they all came back and said "I bet that's what M had..."
I'm debating or not if I want to do elective antibody testing on him/my household. Because I know that antibodies don't necessarily mean immunity (especially 5 months later and how much it could have mutated), but it's almost a weird sense of relief/closure on what happened because it was, without a doubt, the most terrifying moment of my life when it happened, but I never felt like we understood why it happened, and I was afraid of what it meant for the next time he got sick/the likelihood of it happening again.
::: BCH Medical Education ::: (here's an article on it)