Gained weight since joining the gym????

My boyfriend and I joined Bally's the first of July. I will admit I only went a few weeks in July (2-3 times a week), then I was out all of August, was in Guatemala for 2 weeks (walking a lot) and then had bronchitis and PCP told me to take a couple weeks off to fully recover. But still I've done more since July than I've ever done, I've gone to the gym before and done eliptical but I never did much weight because I was scared. But now I do 15-20 mins on elliptical (118-130 heart rate per the suggestion of a trainer...who I only got 2 sessions with...he left Bally's in August while I was out). And then I do 45-60 minutes on various weight machines...upper and lower body. Since joining Bally's I've gained 8lbs....seriously? I can't think it's all muscle, sure I should be gaining muscle but shouldn't the added muscle be helping me burn more calories or something like that? Just frustrating...eating is the same, yes I know it's not perfect but never ever even before surgery had I gained so much so quickly.

You will gain weight when you work out.  You will also slow down weight loss.
It happens you can see it over and over here if you go back through the old posts.
Part of it is muscle, and part of it is exercise will stimulate your hunger.  You will find that you eat more.

I wouldnt worry about the weight gain unless your clothes start fitting tighter.  as long as you are exercising and maintaining a decent level of fitness.  Your clothes are still fitting well or perhaps even better, you are probably better off.  If you find that your weight is going up, and clothes are fitting tighter, then it's time to reaxamine your food and make sure that what you think is the same really is the same.  If you aren't then go back to writing everything down.  Every bite, lick and taste. 

I know personally that my weight loss stalled for a long time when I started working out.  Then one day it just kicked back in.

Good luck and hang in there.

Scott