T.B.
I had a lot of back pain with my 3rd child. It's how the baby is positioned inside, it's also the added weight (baby, extra fluids associated with pregnancy). I found that the only thing that helped was to lie on my left side. With you having a toddler to care for, I can imagine how difficult it must be to rest. I understand. I have 3 children and was quite active after my first. Do your best, rest when you can. I found that walking made it worse so I sat down a lot when given the chance.