For starters I'm 21 year old guy I just wanted to get some info about female orgasm. I've dated my girlfriend for 4 months. Here is the deal. She told me that she had an orgasm with me once. When I was really in the mood and I was more fit (I jog everyday during the summer), I had to sweat a lot, (about 15-20 min) go very fast for her to get it. It seems to me that I got used to her a little more and now I can't do that well and I come to orgasm a little faster. (maybe because I;m not in such a great shape). I want her to get it again, but I can't make it happen. Anyone can give me some advice or recommend some sort of technique please.
Another thing I'm concerned about. I love giving her oral and she seems enjoy it too (sometimes she asks me after a while if I ever get tired of it). When she gets closer to an orgasm I can feel some tension in her body then she starts to breathe very fast that I can hear it even from down there. Then she get some sort of release (what it seems to me at least it only last for a second or two) and she asks me right the way to stop doing it, because my tongue tickles her and it only makes her laugh. My question is, is she getting an orgasm or it called something else?

. She does become very happy and more open minder right after it.
Thanks in advance.