Too Early to Plateau?

I know people will lose weight and then plateau for a little bit and then go back to losing weight, but how soon does that normally happen? I feel like it's been too soon for me. I started working out in Nov 2012 and I joined MFP Feb 2013. Between November and now I am only down about 9 pounds. Although I understand this is great for long term weight loss, it seems with the amount I want to lose (40 pounds), I would have lost more by now. I am 34, 5'2' (not petite), and started out at 185. I'm down to 176 and for the past three weeks my weight was 176, 176, 175.6, now this week 176 again. I know it's not weight training because I've only been a few times.

I started out doing the reg 1200 default calories and then switched to the TDEE method last month. I work out 5 times a week swimming laps, water aerobics, or brisk walking, so my TDEE + 20% put me at 1942 calories a day, which usually I ate between 1400-1700. I don't think I am eating too few calories, so today I changed it to TDEE + 30% and it put me around 1700. I'm going to try that and see how it works.

Has anyone else experienced a plateau so early in the your weight loss journey and how did you overcome it? Thanks!