Mom guilt

Today I have a very serious case of "mom guilt". JR called about 30 minutes after school started to ask if I could bring him his homework. I explained that HT was home sick, and since we are having absolutely miserable weather, I wasn't going to take him out in this weather. I could tell that he was disappointed, and we both know that this is going to adversely affect his grade. I can't help but feel guilty. I've tried to tell myself that it's a good lesson to learn. All he had to do was to put the homework in his folder when he finished, instead of being lazy and just putting it back on his clipboard. Hopefully he'll remember this lesson next time. I try to tell myself that if I had been working today or out running errands, the result would've been the same. But since I told him I wouldn't bring it up, I have this terrible guilty feeling that what he is going to remember is that I wasn't there for him. I know that I'm there for him in hundreds of ways every day, but I can't help but feel the guilt!