Fact or myth? Having sex everyday will lessen the eperm concentration?

Hi! Im new in this community, Im 29 years old and my husband is 30. We've been trying for 3 mos already using calendar, glow and bbt. Someone just told us that if we want to get pregnant we should have sex every other day not everyday coz it might affect the sperm concentration. One more thing does putting a pillow u der your pelvic bone after sex will help the sperm to reach the egg? Myth or fact? I hope you can help me. Thanks 😘😘😘😘