Genesis 29:29-31 New English Translation (NET Bible)
29 (Laban gave his female servant Bilhah to his daughter Rachel to be her servant.) 30 Jacob had marital relations with Rachel as well. He loved Rachel more than Leah, so he worked for Laban for seven more years.
The Family of Jacob
31 When the Lord saw that Leah was unloved, he enabled her to become pregnant while Rachel remained childless.