I just started a new job and about 4 days after starting I found out I was pregnant. I am on probation with work for 3 months so they can terminate me for no reason. I don't know what to do. I feel terribly guilty for not telling them and I don't want them to think I knew when I accepted the offer. Should I wait till my probation is up to tell them so they can't terminate me or should I just be honest and hope for the best.

A side note, I am a high risk pregnancy as I have had multiple miscarriages and we are not telling anyone till after our 3 month scan to make sure the baby is healthy