Yes your weight does need to be in sync with your height but from most things I've read and heard about it, they generally can tell this via looking at you briefly when they meet you. Obviously if you are lucky enough to get to the medical, the doctor will weigh and measure you and all he/she is really looking for is that you're in the healthy weight range [the graph] for your specified height. So don't stress, you have about 8kgs room either way!
This is an Australian calculator [so it's in cm's and kg's] but you can see what your doc will be looking at if you type in your height in cm's.
http://www.mydr.com.au/tools/weight.asp