hard workin mamas?

I have worked with children my whole career, and now I am in Special Education with disabled and troubled children. I have always done some extremely stressful and physical work with these children. It ranges from lifting to restraints in behavior management due to the autistic child self harming or harming others. I am now 6 months pregnant and never stopped working and my doctor has said I look perfectly fine. I'm careful of course but I've started getting extremely tired throughout the day. I just want to know it's OK to still work hard and wouldn't mind hearing some other hard jobs that some other pregnant mom's do out there? Anyone feeling worn out yet?