Eating less but feeling full?

I've just finished my second week on MFP, and so far lost 6 pounds. I've been exercising more, both cardiovascular and light strength/calisthenics at home as well as eating within the net 1200. I am trying to eat healthier overall, but still indulge in unhealthy food every now and then - some days more than others. I am keeping within my caloric limits and generally eating better (healthier food more often, and less of unhealthy food when I eat it) but not full on cutting everything I enjoy as I think this will make me fail.

I worry sometimes that my exercise calories logged aren't accurate (no heart rate monitor) or that food calories are a little bit off (I try to log as accurately as possible - using the packaging wherever possible and otherwise guessing as close to as I can, and always logging everything I eat)! I've also been feeling more full than I expected, eating a lot less than before! Although I'm a little worried that my logging is a little bit off (i.e. overestimating exercise, underestimating food), I always try to err on the side of caution and I noticed that when I normally eat a burger and chips on a Friday, this past Friday I was too full to have many chips at all!

Has anyone else had a similar problem? I assume it's just because I'm getting used to eating less but just wondering if others have had the same problems where they end up worrying about their logging because they don't feel hungry all the time when eating a lot less!

And any thoughts on whether I should be cutting the chips and treats completely or whether slowly reducing them is a good idea?

I've never stuck to any "diet" for more than a week so I'm feeling strong two weeks in and want to give this the best shot I can!

Thanks so much!