Calipers are less accurate than the dunk tank test (and autopsy), but more accurate than body fat scales (e.g., Tanita's) or weight/hip ratio algorithms.
There is a skill to caliper testing -- you need to know where to test, how to relax, how hard to squeeze, etc. And some protocols require you to measure BF over the scapula, which is a bit tough to do yourself! Caliper readings will vary from tester to tester on the same subject, and also depending on the subject's level of hydration.
My point is that if you're just looking for a way to track your progress, it's fine to test yourself. But, don't take these numbers as "real" in any absolute sense -- just pay attention to the change from month to month or year to year. (BF% also changes more slowly than weight, so don't get discouraged!)