Glad your u/s went well, Blackbird.
When I was pregnant with Gab, we had slapcheek going around the school where I worked. It was actually the Principal and the VP's that alerted me to it and told me to mention it to my GP. I too had no immunity. He wanted me to take time off work until it was no longer prevalent in the school! I was in the 1st trimester so right at the danger period. I told my doctor that it was ridiculous to suggest me taking time off work... after all, I was responsible for 28 children who'd already had a teacher change that year. So I sent a note out to all their parents informing them of my pregnancy. I asked that if they had any inkling that their child was exposed to or showing the affects of slap cheek that they inform me and not bring the child to school. The parents all took it SO well and I got many, many congratulations. The virus ran through a few preps and some 5/6 kids but never hit the 1/2 department where I worked so I am glad I didn't take any time off work. I thought my boss handled it all brilliantly - she even gave me a heap of information about the virus.