It could very well be a tiny plateau....sometimes, those can last for months, so 1.5 to 2 weeks isn't a big deal. If you haven't had any until now, consider yourself quite lucky.
Also, have you changed your caloric intake? You have lost a lot of weight and as your weight goes down, so do the amount of calories you need. Also, you might not need to increase the amount of time you workout, but it might make sense to increase the intensity. Our bodies actually become used to workouts so they don't burn as many calories with the same workout as they used to. I really recommend Hight Intensity Interval Training. It only takes about 20 or 30 minutes, but it is a major calorie and fat scorcher. You might also try calorie cycling. The goal is to constantly keep your body guessing as much as possible. Congrats on all the weight you have lost so far!
You are doing really, really great! I think a lot of people give up when they hit a plateau and I feel like this is a big reason why people get off track. Hang in there!!!