Hi Nice to know that you want to know more about getting pregnant. It is said that to get pregnant you should have intercourse during your ovulation day which is around 14 days prior to your expected mensus in a regular cycle. But we usually recommend regular sex after 7th  or 8th day of your mensus  for 15 days. Because it is difficult to know when exactly is ovulation. Secondly it doesnt matter day or night...you both should be enjoying sex and never indulge in with the idea of getting pregnant . your husband should not use any lubricants. And after sex it is better you lie down in the  same position for half an hour and wash your vaginal area after 45 min only. I hope you are convinced ..if not please ask again your queries. Best of luck for both of you.