Question: when did melinda get pregnant on ghost whisperer
[{'answer': 'In the fourth season', 'provenance': [{'wikipedia_id': '27398411', 'title': 'Ghost Whisperer (season 4)', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 20, 'bleu_score': 1.0, 'section': 'Section::::Plot.\n'}]}, {'provenance': [{'wikipedia_id': '27398411', 'title': 'Ghost Whisperer (season 4)', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 832, 'bleu_score': 0.9865312178338931, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2395334158017088531}, 'section': 'Section::::Plot.\n'}]}]