Aiyoh sayang, better check with your doctor or call your clinic first okay, back pain and thigh ache in early pregnancy needs proper checking lah, just to make sure everything's good with baby. Some of my mum friends did experience this, tapi everyone's different, so don't tahan-tahan je. Your doc will know best what's normal for your 7 weeks and what needs attention. Jangan delay, go see them soon eh!