I was in the same boat. I just had the shot on Wednesday and started bleeding (lightly) on Friday. I had blood drawn Saturday and another Tuesday. I am in no pain but do feel awfully bloated and gassy :( I wouldn't travel until I knew my levels were down.My levels weren't almsot as high as yours.
You'll probably be fine, but it's understandable if you decide to cancel the trip. Your doc will want to check your hcg after you receive the shot. My first blood draw post metho was 2 days after the shot, and then each week after that. My levels were higher after the shot, but then started to decrease. If it were me, I wouldn't want to travel until I knew my levels were decreasing.
it really just depends some women it only takes one shot to start the process but some it takes longer and more then one shot. talk to your doctor before you decide to leave though good luck