Discrimination against single pregnant moms

I finally got approved for a new apartment and I get the keys tomorrow. This has been the most stressful move ever since I’m doing it by myself. I am 32 weeks pregnant with my first, but it’s not obvious when I wear my work scrubs. I feel almost guilty because I didn’t tell my new landlord that I was pregnant. There was a section asking how many children, if any would be living in the unit but it asked for their date of birth and she isn’t even born yet so I left it blank. This was the 5th apartment I have applied for but the only time I didn’t disclose I was pregnant. I have great income, good credit, and good rental history with no evictions so I’m convinced that my pregnancy is what was keeping me from being approved. One landlord even had the nerve to ask me how I’m gonna pay the rent once I have my baby..another property manager tried to strong arm me into getting a more expensive 2 bedroom instead of one, once I told her I was expecting. I was tired of the cycle of going to schedule viewings, paying application fees, and then waiting by the phone so this time I feel I did what I had to do to make sure I have a roof over our heads. I just want to know if/when I should tell my landlord I have a baby. According to my lease, I only have to give him notice of any tenants (over 18) staying long term.