Dear Michele! First of all (before you increase the tea stipping time) increase the water intake. I had the same experience and consulted the site: they recommend to increase the water intake first. I did so and had very good results (I mean 2-3 b.movements a day). Eventually you will increase the time to 6-8 min. But do not do it from the beginning. I am starting my second month next Saturday.
Good Luck to you! Polina.