HI. My name is Catherine 24 cf.
The period thing, all I can recommend is that you go see your gynocologist about it. I have had mine since I was 12, and it has always been EXTREMELY painful and very heavy, which I have been told was because of the CF.
The tummy. Don't we all wish we could have a flat tummy, but UNFORTUNATELY with CF, it is a very hard thing to do. For some it is more dramatic than others. As my doctors always say, exercise (blah ;-) ) is the best that you can do, besides take your pancrease and other medications. Steriods, like prednisone, will also help extend your stomach, as one of the side effects is that you are always hungry.
And again...unfortunately...as the disease progresses we all will become sicker and our bodies will not react the same to the antibiotics as for some we become tolorant to them. You can try some healthy things like taking MSN, which is sulfur, to try and boost your immune system. (it will also make your bones stronger for the osteoporosis) Talk to you doctors and see what they suggest about helping to boost your immune system, besides doing the incredible amount of antibiotics and steriods. Look around your environment and see what can be changed that could possibly be helping to contribute to you being sick. Like, are there a lot of smokers around you, etc...
That's all I can suggest right now. Hope it helps a little