My interpretation of the events and GPs question is that the timeline of intercourse/conception wasn't suspect, only the efficacy of the contraception. The only

My interpretation of the events and GPs question is that the timeline of intercourse/conception wasn't suspect, only the efficacy of the contraception. The only scenario where deception and the suggested test of such makes sense in this case would be if the partner had stopped using contraception earlier by choice and had an affair.