Most people are exposed to this prior to pregnancy which gives you immunity. It is extremely common and immune status is usually tested for in first trimester bloods.

If you are exposed for the first time during pregnancy it can lead to miscarriage, or deafness/hearing loss in the baby (risk is relatively low).

My DH had this when I was 5 months pregnant with our son. It was a massive freak out until I could get hold of my first trimester blood test results to see if I was immune...which I was.

Hope you're ok.