Milly, yes, a trip to the flight deck is part of your supy flight program, so you can get an idea of the workload of the pilots during takeoff & landing, and know where things are (equipment, how to adjust the seats etc)
Depending on the flight you are also given the chance to do walkaround with the captain to see the aircraft from outside, s/he will show you the major parts and features of the air craft. It's fun
Re: haemoglobin. Mari is right. You NEED to be in the range specified on the sheets. Low hameoglobin is usually because of lack of rest/sleep and poor diet. Some red meat should fix you right up.
Some chemist sells a test for your haemoglobin, you can check it yourself before you go for the proper blood test.
Do as others say and eat & sleep well for a week or so before you re-take the test. Just tell them you having trouble getting an appointment. Is difficult for women as most of us will be iron-deficient as some point. Every so often I will get that way and usually the dr will either give me a supplement or tell me to eat more of red meat... usually is related to having a heavy period at the same time as working a lot. I doubt they would send you home for it after joining (if your levels are fine at joining) so long as it was only temporary and not ongoing for a long time. (My guess is they would refer you to clinic for a meal plan/medications to see if it helps before sending you home.)
If diet/rest does not help then obviously it could be some other problem. But like you said, what happened recently could have affected the test (e.g. if you tested right after your monthly.... bad idea! hahahaha)