Pain!!!!

34wks+5 I know this is common but I've been experiencing a lot of back pain and butt pain since Thursday also it hurts a lot when I walk! My Dr. Prescribed me Norco for pain to take q4h but I really don't want to keep talking that being that I am pregnant and also I'm a secretary so I don't want to be sitting at my job being extra tired! I'm soooo confused as to what to do.. He saying that I could go to L & D to get checked but he doesn't see a purpose