Oftentimes, paphs have their buds tantalizingly sitting there, not opening for weeks at a time. Have patience! Unless you notice it shriveling up, turning brown, etc... chances are it's just getting ready to open. Mine was in bud, and sat there for about three weeks, before finally opening! Paphs are just one orchid that really likes to tantalize us orchid growers. :-) Just have patience, and I'm sure it'll open.