Have you been in contact with the Wehling clinic about the pain? I would have thought that they should be supporting you in this even if it is only by email or phone call.
This procedure is not yet licensed in the USA yet, so I doubt if anyone has much experience beyond reading of it. I believe it is similar to the Regenexx treatment, so maybe you could contact the Centaro-Schlutz clinic in Colorado to see if they can offer any support or advice.
As for seeing changes already in the knee, a little premature don't you think? I don't think even the most fervent supporters believe it to be a magic bullet!
Good luck I hope the pain settles down soon. It may well be that the stress of the return journey has played a part in this and now that you are home again, things should quieten down. If they don't then you do need to contact the Wehling clinic and ask whether this is a common problem and what should you do about it.