Is it dangerous to check your blood pressure too often? what constitutes as "too often"?

See psychiatrist : I imagine there is some reason for your concern to be checking your BP frequently. Blood pressure checks are non-invasive and harmless, so the only thing that frequent BP checks will do is waste your time if the BP is normal. Your anxiety may be the reason for abnormal BP's, so you need to find a way to relieve your anxiety safely. I suggest you discuss your stress issues with an MD, seek relief

Not dangerous: But it may very well make your blood pressure go up related to stress/anxiety of elevated numbers. Try to avoid perseverating/"focusing too" much on individual numbers but rather trends over the course of days or more. A couple times per day, is more than enough to trend things blood pressure wise.