That's great, loose and comfortable is the best way to go to the gym due to sweating and overall humidity. Tight clothing at the gym are really uncomfortable and even worse when you're sweating your ass off and gotta take them off in the locker room and they're all sticky. And to tell you the truth, even though you might not care, it's more attractive when a girl goes to the gym to actually work-out and not to simply get looks.
Two, even if you didn't, it doesn't matter. When you're working out, it doesn't matter what you look like, because you should be more concerned with yourself than what others see. After you finish and shower, you can worry about looking presentable. But during the workout, not so much.
Plus, frankly, that outfit makes you look more like you mean business, as opposed to the skin-tight stuff that makes your workout seem more like a show than hard work.
So yeah, you rock that gym-shorts outfit, girl! And don't let anyone's opinion of your workout clothes stop you from wearing something comfortable. Your in that gym for you and only you!
No, that looks normal. Some of the women at the gym I used to go to would like... fucking pose on the elliptical for guys. Full face of make-up and everything. Fucking ridiculous. PS. not hitting on you or anything... but I think you're pretty, awesome collarbone area :p