I'm a horrible mother...

So yesterday I was past my patience limit with Mia... she wouldn't nap, she wouldn't let me put her down...she just screamed and screamed and wanted to be held ALL day. Well this morning I had my little princess back and thought, gee that was weird. I wasn't sure what caused the odd behavior but I was just pleased that it seemed to be over. So, this morning, I reached into the back seat to take her out, while running errands and she was making these strange faces with her tongue. Lot's of bubbles and then I thought I noticed some 'fuzzies' in her mouth, I tried to take it out, but it wouldn't come out...I look closer and whadaya know...a tooth!!! The poor thing was probably in so much pain yesterday. I didn't even think of a tooth... here she was wanting her mommy to comfort her and I was spent and getting upset with her, cause I thought she was just cranky... I feel like such a horrible mother!