Hikers typically stay one night in Pheriche, proceed on the next day to Namche Bazaar and finally arriving at Lukla on the third day. However, if you feel confident, consider passing by Pheriche and continue to Pangboche for sleeping. That will save you some more hours of walking on the following day to Namche Bazaar. That part will be continuously downhill, nevertheless, remember the crossings of valleys. So, again there are uphill passages you will need to manage. When finally arriving at Lukla, plan some spare days, as the weather can be unpredictable and flights might be postponed or canceled.