Will I Keep On Gaining Muscle Weight Forever?

From my exercise?
I ask because I am on a 1600 calorie a day diet but when I increased my exercise, the weight loss stopped. (I only wish to lose 2-3 Ibs more).

I am now fearful that the scales will just keep going up and up and up as long as I keep doing my exercise bike and walking?

No, it won't...
Your body will build the muscle it needs to do those activities and then stop building anymore..
Quick fixating on the weight on the scale! Muscle is a lot denser then fat so gaining a couple lbs of muscle isn't a big deal at all. Muscle is also more elongated and clings close to the frame rather then sticking out in odd jiggly bits like fat does. Each lb of muscle uses 50 calories a day just to maintain.. So, if you gained 10 lbs of muscle you could actually eat 2100 calories a day and maintain.. Not to mention, you would still look slimmer. People who see you only see the size you are not the number the scale says..
I didn't gain any muscle at all walking, but, I walk at least 8 hours a day thanks to my job.. I had to take it the next step up and start weight training to continue gaining muscle..

If your eating 1600 calories and you exercised, and weight loss stopped is because your metabolism has slowed down.

Increase calorie intake to 1800-1900 with the same amount of exercise to boost your metabolism and convince your body to start burning fat.

The metabolism can be very tricky....

Why does it matter? Does the scale determine the shape your body is in? NO.....The most important thing is to have a good bablance of lean muscle mass. Your weght will fall in line with that. Quit weighing and keep working out. Also.....eat more protein and more fiber. The carbs may be killing you. I hear that calorie counting mess and immediately know you are eating alot of carbs.