We apply the causal interpretation of quantum mechanics to homogeneous and
isotropic quantum cosmology, where the source of the gravitational field is
a conformally coupled scalar field, and the maximally symmetric hypersurfa
ces have positive curvature. In order to symplify the system of coupled equ
ations studied and study the quantum behavior near the singularity, we rest
ricted ourselves to the cases where the scale factor is small. In this case
, the general solution of the Wheeler-DeWitt equation is a discrete superpo
sition of Hermitian polynomials multiplied by complex exponentials. Superpo
sitions with up to two parcels are studied, and the phase diagrams of their
corresponding Bohmian trajectories are analyzed in detail. Nonsingular per
iodic quantum solutions are found. We also find that singular quantum solut
ions present an inflationary era in the begining of the Universe. Numerical
calculations indicates that these results remain valid for general superpo
sitions.