Hi There, I Need Done Advice Regarding A Health And

Hi there, I need done advice regarding a health and safety issue at work. I am 16weeks pregnant and am due to return to work tomorrow after my Christmas break. I was just informed by a colleague that our toilet has become blocked and is consistently overflowing, pumping out raw sewage into our bathroom which is beside our workspace. A small poorly ventilated area.
Due to people being on holidays the problem cannot be fixed until Monday, leaving us with no running water or toilet facilities. I am worried about being around an unsanitary area and the harm this may cause my baby and my health. Can you advise on whether I am over reacting or have cause for concern?
Many thanks , Ellen