The first thing I notice is that you said you lost three pounds in two weeks, which is great! Then I see you are discouraged because you think you are not losing any weight. But you lost 3 pounds in 2 weeks - that's something to be happy about.
You said you were on SBD "without cheating" for two weeks then stayed on it another week. Were you in phase 1 for 2 weeks, and then did you move to phase 2? It might help us to give you some suggestions if you were to post some more information, such as a sample menu showing what you eat in a typical day now (including amounts and anything you might have added to the food, such as oil or condiments).
I've seen a lot of people talk about how fast they are losing weight, and it seems to be very dependent on things like age, sex, overall health, any health conditions, level of exercise, how much weight you have to lose, etc. It can vary quite a lot. And it doesn't necessarily happen steadily or predictably - sometimes the same person will lose weight quickly and sometimes slowly. The important thing is to keep eating a healthy diet and keeping active. You should also be sure to check with your doctor about your eating plans.
Welcome, and best of luck to you!