I didnt really notice my back pain with my 1st as i worked in a Restaurant as a Food and Bev Superviser so i didnt really have time to pay much attention, but with my 2nd i noticed alot more pulling and tugging!
If u cant afford a physio, try a few little exercises at home!! u can google excersise and most pregnancy book say what u can and cant do, and theres always heat packs and some musle creams u can use!!
Hope all goes well