Weekly vs daily net calories

Do any of you concentrate more on your weekly net calories rather than daily intake? Last week I had a couple of days where my calorie intake was a lot lower than I'd have liked due to stomach issues. Looking at my weekly net intake for last week, it says I was 1508 net calories under my weekly goal. I'm guessing this isn't necessarily good? Last night I went to bed hungry despite eating my calorie allowance for the day and this morning I woke up starving! Could it be that last week is catching up with me? Also my diary is open and I'm aware that the food I've been eating recently is NOT the healthiest [I am ashamed!] but I've just started a really intense uni course and I'm finding it really hard to eat properly at the moment.

Thanks :)