Should be ok afaik, I have had lots and lots of early scans over the years. With me I have had the vaginal scans' before 9 ish weeks and normal ultrasounds afterwards. Might be worth asking what proccedures the scanning dept has though before you book it. Good luck and hope all is well
At 10/11 weeks you should be able to see how many, where and check heart beats with an abdominal scan.
The only disadvantage is that if you cannot get a scan while you are away you will miss the time period for the nuchal screening/combined test for Down's (IIRC it needs to be done between about 11 and 14 weeks). I don't know whether its offered where you live, or if you'd want it even if it is - but if you would choose to have it it might be worth looking at options. Are you traveling to a location where it would be possible to get the scan done locally?