I have just checked out the website for Camara Municipal de Leiria in whose area Praia de Pedrogão lies. It turns out the the main bus operator in the area appears to be RodoTejo. According to the RodoTejo website ( http://www.rodotejo.pt ) there is only one bus per day on weekdays from Leira/Monte Real to Praia de Pedrogão and one bus back. Even in summer, it appears bleak.
The bus depart Leiria at 10:15, arriving PdP 11:10.
The return bus departs at 12:20 arriving Leiria at 13:17.
It is probably better to come from Porto, as you can get a metro from the Airport to Porto Campanha and then change trains at Coimbra-B and Bifurcacao De Lares before disembarking at Monte Real or Leiria to get a taxi to PdP..
I have published an extract from the current CP rail timetable here:
http://scr.bi/9jHktL
