Hi Inge. I have experienced this.
Well certainly everybody is different. Some may know pretty quick that "this is my teacher", while for others it may take a while. I think in that sense it is based on each one's conditions. In the first case, one may have a strong connection to a certain practice, or even a strange sense of recognition, or maybe other signs. It's somewhat difficult to explain, because often times I think it can be a very personal experience for some. In my case, it is kind of personal I guess, but from my experience I had a few of those "whoa!" moments which kind of smacked me in the face so to speak and there was little doubt.
Some may overlook a teacher because they wish to be the student of a particular teacher, or because a certain teacher isn't as "famous" as others and so forth, but once again, our conditions must be appropriate....other times, one may come across them but are not entirely sure in the onset.
My suggestions are to keep practicing with a pure heart, a pure mind and a pure motive, and make sincere prayers and aspirations that you may find your teacher (or is it your teacher may find you?) I think this sounds very simple, but it is very important. I think they will find you. Try to be patient. It'll happen when the conditions are appropriate. Have faith, and do make heartfelt prayers and aspirations, though! the Buddha's and Bodhisattva's will hear you!
For what it's worth, I like to recite a particular dedication prayer that contains a line wishing others to meet with great teachers and glorious guru's. I will try to remember you as well... (I will try to find it and post it-it is a most beautiful dedication prayer...)
I don't wish to argue with the points made by Kevin, because I think that everyone's conditions are different and so forth, teachers are different, and some may view things in a different manner so, my take...
Some do have affinity with many teachers, a few of which they may be fortunate enough to have the circumstances to meet in this particular life. Sometimes it may be helpful to receive teachings from various teachers, but other times it may be just as helpful to have a few, or even one teacher, and follow them to the very end.
Some empowerment's may come with commitments, but they all come with Samaya with that particular teacher. In a strong sense, the teacher takes "responsibility" for the student at that point. This being said, the teacher may often wish to examine the student for a period of time beforehand. One thing I've always wondered about having multiple teachers, is the basis for the first Samaya precept; Essentially to follow the teachings and the wishes of the guru. Sometimes I think that the fewer teacher's one has, the easier it is to keep this vow, which is the basis for the entire set of vows.
I've never done so myself, but I know that sometimes it is possible to arrange for an interview with a teacher, providing their schedule will allow for it. Perhaps if you request it with sincerity, this may also be a very good option for you.
Best of luck, may you have the causes and conditions to meet with your teacher quickly!