What kind of person makes their mother cry?

That's right, people. I'm a terrible person. 
The other day, I called home to ask Mom a question. I knew she probably wasn't home because she was helping my niece with some car-related issues. But I called on the off chance that she would still be home and could answer my questions. The phone went to voice mail and, instead of leaving a message, I hung up. Did I think anything else about it? No. Not even for a minute. 
At five, when I got off work, I called Mom to see how things were going and do my regular check-in. When I asked how she was she said, "Fine, now that I'm done crying." That concerned me, obviously, because I love my mom to pieces. I didn't want her crying over anything! Then, she proceeded to tell me the reason she was crying: I called and she wasn't home, so that means she wasn't there for me when I needed her, which made her cry. 
Holy crap. I suck. 
What kind of person makes their mother cry? Even accidentally? A horrible, horrible person. A terrible, horrible, no good, very bad person. Since then, I think I may have redeemed myself. Maybe. Or not. I tried to please her this week. Personally, professionally, all around tried to please her. Basically, it was an effort to prove that I didn't really suck as much as I felt like I did for making her cry. 
Does this mean I lose the daughter of the year award? Because, seriously, I was on my way to winning until this happened.