Firstly congratulations on your wee boy!!!!! I somehow missed this news completely!
I got my AF back 15 weeks PP and my hormones were all over the place but I was ovulating, but my LP was only 8 days...
Whether on domperidone or not there is not guarantees your AF will come back in the next couple of months anyway so coming off it may not help.... After speaking with my naturopath I went back on vitex and B6 when we started TTC again (Jake was 5 months) but I am not sure it actually helped tbh. Vitex can help with supply too she told me.
When you are ready to TTC you could always get your prolaction levels checked to see how high they are....
In terms of "normal" levels during pregnancy this link might help
link
Again, huge congrats... made my day