No, garbha-kalyāṇak and 14 dreams are not the same, but they are related.

• Garbha-kalyāṇak means the auspicious event of conception when a Tīrthaṅkara’s soul enters the mother’s womb.
• 14 dreams are seen by the mother as a sign that a Tīrthaṅkara has entered her womb.

So:

• Garbha-kalyāṇak = the event
• 14 dreams = the auspicious signs associated with that event

In Jain tradition, the 14 dreams are considered one of the divine indications of a Tīrthaṅkara’s arrival, especially described in relation to the Tīrthaṅkaras’ mother.