Ive just saw her today just for a while because I arrived late to the gym and she was almost finished with her routine. These are the things I noticed:

-When I arrived and waited at the door for someone to open it (its a glass door) she was working out and was looking at me, while she thought I didnt notice.

- I didnt go an say hello to her. After a while, while I was taking some weights she appared at my side and said "hey hello". She told me that she was almost finished and I said "well done girl" and gave her a caress on the top of the head (like when you congratulate a child) she seemed to like it.

-Then I talked to her for a while and joke around, When she was leaving, she said "hey bye" from near the door and I make her a sign to come to me. She did and we talked for a while, touched her hair while maintaining strong eye contact, she seemed pretty comfortable. Her hair was "up" (im not an english speaker but is when they wrap their hair in something). What I said was "Why you have your hair like this,... I like it the other way" she giggled and continue to talk to me, while her hands were unwrapping her hair.
Asked her if she wanted to wait for me for a while but she told me she was going to the hair stylist...

So we just said bye , gave her a kiss while caressing her arm.. the kiss didnt felt short, like "appropiarte" long.

Any ideas?

She is so obviously into it. Just continue down the path you are on.

The paradigm of attraction is always there and it wants to happen. The key is to get out of the way and let it happen.

Shes confusing. I didnt see her for 2 days but I texted her last afternoon with a "hey". But no response. I stopped there.

So today I went to the gym, and she was there. Didnt say hello, after a while she came closer to another machine near me, but I waited for a while before going and talking with her.

She was done with her workout , we spoke for a while, and asked her out "Im gonna go out for a walk later... I want you to come with me". Thing is while I was saying this she was like nodding her head, looking at me (we always have strong eye contact) and said "Im sorry I cant I gotta get ready for traveling this new years..." .
I knocked her head with a finger and said "damn youre a busy girl" and she smiled.

This is like the 3rd time I asked her out, 1st she was busy with the xmas shopping but gave me her number, 2nd time she had to go out in xmas with her family and now shes gotta do her shit for new years eve trip.

Should I just go next? even if she seems interested when we talk?

From what I can tell you've asked her out four times in the last few days if you include her declining of waiting for you when she went to the hair stylist. I'd just let it cool down as far as the suggestions to go out and meet more women. Maybe in the new year if she still seems interested, get her to commit to a day to meet first rather than saying "lets go do x on tuesday".