Miscarriage

Tomorrow is my first shift back at work since I found out I was pregnant. I have heart problem and was signed off work the day I found out I was pregnant. Had made arrangements with work and my cardiologist to go back on light duties after 4 weeks. Went for my appointment on 6th January and found out my baby didn't have a heart beat. I was 10 weeks pregnant but I suffered a missed miscarriage as the baby was sized at 7 weeks 5 days. Had to have a procedure to remove the baby. So nervous about work as I don't know what to say if anyone asks why I've been off for so long :(