I didn't have it at all with my first. I developed it in the last couple of weeks with my second PG and from about 18 weeks with my third.
I had quite a bit of pain between my send and third PG's also, enough to postpone TTC for a while till I thought I was past it. Unfortunatley it wasn't the case

The main difference between a chiro and a physio is that chiros do more manipulating of the joints. Physios can do it sometimes but that isn't their aim if that makes sense. If a joint cracks in the process of you being stretched or massaged then it can help. Generally for me the physio helps to relieve the muscles that are tired from holding onto the joints.
The reason that I love my chiro is that he will rub down and warm up my muscles for a good 10 - 15 mins before he tries to manipulate. It makes a huge difference! He is in Narre Warren if you're interested but it may be a bit of a trip from Northcote PM if you'd like his details.