Yes it is fine to receive communion on saturday and sunday, even if the saturday mass is a vigil mass. According to canon law you can receive communion twice a day if the second time is within the Eucharistic celebration.
Can. 917 One who has received the blessed Eucharist may receive it again on the same day only within a eucharistic celebration in which that person participates, without prejudice to the provision of can. 921 §2.
Matthew