(Concern) Lately, I've been worried because my gums bleed sometimes.

I brush my teeth diligently three times a day, but sometimes my gums bleed. Also, when I am stressed, my gums become swollen and sore, making it hard to sleep. It's not cavities, so do I need to do special gum care? If so, I don't know how to do it properly. There are gums strengthening toothpastes and mouthwashes available on the market; would they help?