Started out with calories too low, now what?!!

Hi all, need some advice.. I went from eating anything I wanted and never exercising to changing it all on January 2, 2013. I began with MFP and started tracking calories and exercising 5 to 6 times per week. I do a combo of Matt pilates, equipment pilates, weights and cardio.

I have lost 12 lbs so far but have recently slowed down. I started out not dropping my calories gradually but instead went right to 1635 calories a day and have been eating that amount ever since.

What do I do now? Is that caloric intake still accurate to lose or do I up it and try to drop again gradually to trick my body? Any help is appreciated!! Thanks