Scarab, I can relate to that hip and leg pain. A few days ago I started to have the same problem and it was then that I remembered I had experienced this with my previous THR. As I type this I'm lying in bed waiting for said pain to abate because I stupidly got behind with my meds and am now in catch-up mode. For some reason my timer didn't go off when I was due to take my codeine three hours ago so I got to my 9pm MST Continus, plus paracetamol doses (Panadol/acetaminophin/Tylenol to cover the various names for this throughout the world), and was already over the edge. But I'll be fine shortly.
Now, let me just tell you about my pain relief last time round. Like you, I began to worry that I shouldn't be taking meds for so long. I had read so many stories of people who left hospital without needing anything and were swinging from trapezes within a week of surgery. Well, I'm not one of those people and I was lucky to have a care team who understood that everyone has different needs. I was discharged with a prescription of 1,000mg paracetamol every six hours, 30mg codeine every six hours, and 10mg MST Continus twice daily. After about four days, when the above mentioned back and leg pain began to rear its ugly head, I had to speak to my GP, who gave me more MST, plus Sevredol 10mg to take three times per day as required. He gave me a month's supply of each. It was such a relief to be pain-free. However, within a few days I began to worry about becoming addicted and bought a pill cutter to wean myself off the drugs, maybe in a week or two. But I never used that pill cutter because eventually I just naturally started skipping doses without even thinking about it and, in fact, I don't even think I used up half of that prescription. Yesterday I had to speak to my GP about nausea and he changed my anti-sickness meds, plus gave me Sevredol again. Yay!
So, please don't worry about anything but alleviating your pain and recuperating. Everything else will follow. But, the best piece of advice I was ever given where medication is concerned is don't skip the paracetamol. Seriously, acetaminophin is a drug that we all take for granted for minor aches and pains but it is definitely undervalued. So keep taking that four times per day - yes, set your alarm so you don't skip it - and you'll see how few of the rest you'll soon need.
Good luck!