1999 Honda Civic Possible Head Gasket

^ what db4690 said those test are good however not always 100% because I am certain I have a blown head gasket but none of the telltale signs such as milky dipstick and white pummels of smoke. But that and a pressure test MAY determine if there is antifreeze/water being used up somewhere in the engine and a pressure test will show you where antifreeze may be leaking, you can get these things for free at autozone as long as you bring them back at the said time.