Ache in upper back and constant pains in right leg

Hi Everyone... Im new to this, after reading many posts hoping to find someone with simlar symptoms, but as of yet, nothing. For the last few months, I have had this deep ache on my middle back between shoulder blades and radiates around that area. Its not painful, but more burning/nagging pain that comes and goes. Also linked to this is a deep pain in my leg that is pretty constant, right behind my knee one day, calf the next and then upper thigh into buttock. Difficult to sit, and stand, I get relief I think when i go to bed. Ive done every blood test possible including enzymes to see if its a blood clot and all was fine. Chest Xray was all fine. I suffer reflux. I'm really worried as tomorrow i embark on a 15 hr flight and dont know how my leg will cope. I have seen the chiropracter 4 times and an osteopath 3 and no joy whatsoever. Can these pains be linked and does it sound like sciatica?? I thought sciatica only comes with lower back pain, but i dont suffer that. However, my lower spine does click most days after sitting at my desk for a few hours.. Its really getting me down. Im off on my 40th birthday holiday tomorrow to easter island from UK and I just cant deal with this pain and worry...Any ideas or advice would be greatly appreciated. Cheers everyone. Jason