Rajma is perfectly safe and a great source of protein. If you have severe acidity, you can always ask your hospital nutritionist for a customized diet chart.
Yes, you can eat it during pregnancy, but try to avoid heavy beans like rajma immediately after delivery, especially if you had a C-section, as it can cause painful gas.
I could barely tolerate the smell of rajma early on due to my severe nausea. But if you can digest it, go ahead—just eat a small portion to avoid heavy acidity.