(a) All children born in wedlock or within the usual period of gestation thereafter are legitimate.
(b) The legitimacy of a child born as described in subsection (a) of this Code section may be disputed. Where possibility of access exists, the strong presumption is in favor of legitimacy and the proof must be clear to establish the contrary. If pregnancy existed at the time of the marriage and a divorce is sought and obtained on that ground, the child, although born in wedlock, will not be legitimate.
(c) The marriage of the mother and reputed father of a child born out of wedlock and the recognition by the father of the child as his shall render the child legitimate; in such case the child shall immediately
take the surname of his father.