Hi ya I would say as a general rule it's best not to as the temptation is to think it's ok I've got those extra calories etc etc. If you have a special event coming up then plan your week well ensuring you leave the extras (I generally save my treat calories).
I notice you say you are on 1628, I take it you mean this after the initial 2 weeks on the 1200 calories.
MY biggest tips would be - do your measurements, it's a boost when you feel that you haven't lost weight or the scales say you haven't and you remeasure to find you have lost inches.
Treat yourself - have little gifts along your journey. My first stone meant I had my eyebrows waxed professionally, 2nd was a manicure, 3rd was 3 new items of clothing and a pair of shoes in one shopping trip etc etc.
Drink! - water water water I carry a small bottle with me everywhere and top it up as I go along through the day.
Find an exercise that you like and think you can stick to - mine is aqua aerobics and I get annoyed if I miss a week.
Don't beat yourself up if you don't lose for a week or two
Oh and save some calories or your treat for the evening when you are sitting in front of the TV.