I have someone check it for me when I can. The digital BP monitoring apparatus is usually reliable when the batteries are new. But I wouldn't bet my life on those automated BP checking apps. I'd rather have it checked by a manual sphygmomanometer from a trained personnel because that's more accurate than digital. You shouldn't rely on what you're feeling to know if your BP is good or bad. Sometimes you just feel fine but your BP could sink so low or go high without your noticing it. The reason for being well even when your BP isn't good is that your body is compensating the problem making you unaware. But as soon as compensatory mechanisms fail, that's the moment when the illness becomes noticeable.
I've seen patients behave normal and claim to feel normal with high blood pressure that requires immediate hospital confinement. Just make it a habit to check on your BP once in a while regardless if you're feeling fine or not.
I feel good. I rarely check it. I don't feel it is necessary. Since I feel good, it is probably/should be good/proper.
Sometimes it is required/necessary to check it, but I don't even remember/know when was the last time, when I checked it. Approximately a few weeks or one-two month(s) ago, but as I remember/know, I didn't checked before that for years. Or I don't remember. I usually check it every few years.