This is a common thought. Not much evidence supports it though. It has been speculated that the elevated levels of progesterone contribute to helping pregnancy develop again. Personally I found that getting pregnant after my miscarriage was rather easy.

My doctor told me that a miscarriage 'primes the uterus' for another pregnancy. Not quite sure what that means but those were her words lol. I'm currently 5 weeks pregnant after my MC on 3rd September