Having AF isn't really high risk for catching covid, although, infection when a person has AF can potentially cause AF to become uncontrolled regardless of what medication you're on, might be best to stay clear, although I'd of course check with your midwife, I'm a a&e nurse so see a lot of AF but can't speak for pregnancy related conditions x
I was covid positive during my first pregnancy at around 35/6 to 37 weeks. I was told there was no risk to baby but can’t speak for other conditions you have x
I had Covid really bad at 26 weeks and my midwife said there are no risks to baby. Baby will take all it needs from you and it’s you that would suffer. I can’t comment on your AF though!
If you are happy to do so you are eligible for a covid booster vaccine. My midwife recommended I consider one.