28+4 pregnant severe constipation

I was taking my prenatal pill in the beginning of my pregnancy but stopped (with doctors approval) because they were making me really constipated and nausea. I went to do my glucose test and more blood work done and it came back that I was anemic, so I was put back on the prenatal. Once again I’m extremely constipated and nausea. I haven’t gone to the bathroom in 5 days. My stomach hurts so bad and I just want some relief. I have been drinking lots of water and eating fiber rich foods but nothing helps. Is anyone else going through this? Is there something anyone of you ladies taking that helps?