Okay, great. I have an appointment with my doctor Friday so I'll find out then, but looks like there's a risk of blood clot so I'm going to see what they say.
I second Vientiane. I'm flying back from there tonight (I flew into Udon Thani and took a van across the bridge) and it was super easy. I believe Monday is when the groups go, so go on a Tuesday. It took under an hour and picking it up the next day took like a minute, it was so fast. They didn't ask for proof of anything -- just need copies of your passport/departure card as well as two photos.