How do you know when it's time to increase calories??

I've been alotting myself 1800 calories per day since I joined the site at the end of September (lost 7lbs so far; woohoo!). In the last 2 weeks I've been really consistant about working out. 

I think my metabolism may be speeding up, but I'm not sure. What are some of the signs that it's time to increase my calories??

If you've reached the weight you want to be then that's usually the time to increase calories....  If you want to keep losing weight then don't increase the amount you eat.