I thought I took every precaution. I still tested positive for COVID-19.

I had sung away Monday morning with ABBA’s “Waterloo” on repeat, dancing as I mopped the floor and swept dirt off the porch. After spending over two weeks in even stricter isolation than usual, I was going to visit my grandparents, whom I hadn’t seen for months, and I was cleaning the house before leaving in the afternoon. Then came the email: my SARS-CoV-2 test, which I’d taken as a precaution before seeing my grandparents, and not at all because I was symptomatic, was positive.

What? It had to be a false positive. I hadn’t spent any unmasked time with anyone but my mom, and we were staying at her house on a farm, hundreds and hundreds of yards away from anybody. In fact, we’d hardly seen anyone at all, except the occasional neighbor from all the way across the street. I cleaned every package obsessively, washed my hands so often that the skin on my fingers cracked open, and turned in the opposite direction if I was walking and a car passed by with the window down.

I thought I’d been careful, and indeed I had been — degrees more so than most, if not all, of my friends and family. They were frequently going out to eat in the city, something I didn’t feel quite comfortable doing, so I stuck to walks and breakfasts in parks and five dinners since March on a restaurant’s patio if, and only if, its tables were adequately (i.e. way more than six feet) spaced apart.

But the one time in the past two weeks that I’d been out to dinner — at a restaurant with tables spaced 15 feet apart, if not more, where I’d called ahead to request that the table be as far apart from others as possible — seemed to have done the trick, and now my nerves began their shrill cacophony. I felt fine, but I conveniently recalled some article I’d read months ago, describing COVID patients who came into the ER feeling healthy but exhibiting ridiculously low oxygen levels. How would they think to go to the ER if they felt so great?

Could I be one of them? Should I go to the ER? Does the risk of secondary infection outweigh any potential benefit of treatment? I thought my breathing was fine, but now, thinking about it — and becoming anxious about it — my chest felt tight. I had sneezed the day before. My arm felt really weird. If I left the thermometer in for a minute after the beep, as my mom instructed me to do, my temperature climbed to 98.7, and after adding a degree, another mom trick, it was a low-grade fever.

I panicked myself into symptoms, and I don’t know if they were real or — a word I love to use because it makes me feel in control — psychosomatic.

Maybe for some, a presumptive case of COVID-19 isn’t all that stressful; for many of us, however, pandemonium invades us along with the (probable) virus.

I was filled with anxiety, compounded by confusion (how on earth did this happen, when I thought I had been doing everything I was supposed to?) and disappointment (I didn’t know when I would be able to see my grandparents again — let alone spend time with my dad, my brother, and my friends).

My experience testing positive for COVID-19 left me with a lesson (“hey, life isn’t fair”) and loaded me with regret. Regret that I saw my cousin, even with a mask and three weeks before, regret that I got takeout instead of cooking and saw one of the restaurant workers unmasked — regret that I let others persuade me to relax when New Jersey began to “open up.”

To alleviate that regret, even a little, I’ve decided to tell everyone I can what I wish I’d known: “being careful” isn’t always enough. You also have to be prepared. So many people, like my dad and my older brother, who work in hospitals, don’t have a choice but to expose themselves to the virus and constantly think about their risk. Many of us are lucky enough not to have that constant threat breathing down our necks; even so, we too must be prepared, and, I would say, more careful than we might think we have to be.

I wish I’d realized all this before, and I beg you to realize it now. I know you probably want to see your friends, you probably think it’s fine to eat out if everyone’s wearing a mask, and it probably is, depending on where you live and the precautions you take. But you should more-than-probably think, think, think about how you’d feel if something went wrong.

That vegan sausage and bruschetta were delicious, but relative calm tastes a hell of a lot better. To sleep without waking up breathless 15 times a night — from panic or COVID I still don’t know; to shoo away an insect by blowing on it and not stressing out that I’ve just given the insect a death sentence (who knows how they react to COVID?!); what a world it was before! So, if you can, please just think a little. And trust your instincts (if they’re good instincts, that is). I wish I had.