Re: Going to see midwife on Thursday...
If it was Fifths and you had not been previously exposed, you probably would have miscarried by now. The fact is, though, if you've got school-age kids, there's an excellent chance (something like 70%?) that you've been exposed at some point in the past.
This virus does not have a super-long incubation period - about five days, IIRC. You're almost certainly fine. Good luck!