New boss is driving me crazy

My new boss is driving me crazy. I started a new job May 30 and she knew I was pregnant. I’m 33w4d, so I’ve reached the point that I’m having biweekly checkups, which will soon turn into weekly appts and then I’ll be on maternity leave 8 weeks. Ever since I told her I was pregnant, she treats me completely different than everyone else. She doesn’t joke with me like the others, if she has something to tell everyone she completely bypasses my office and goes to the others first. She gives me the crappiest assignment out of anyone. One day, after I’d been working my butt off, she had me listening to 27 voicemails and taking down info while everyone else sat in their office doing nothing. I’m not a secretary. Any time I have an appt and let her know the date/time, she gives me this aggravated look. She has four kids, so she should know that checkups become more prevalent at this stage. She makes it a point to remind everyone she will be taking over my caseload while I’m on maternity leave.

I’m just tired of it. I’ve been documenting it and if it continues, I’m thinking of going to HR. Anyone been through this?