TTC with a short period?

Courtney • Rainbow baby

I only have a 3-4 day period usually since I've gotten out my nexplanon. I'm pretty sure I miscarried this month since I was 8 days late which was very unusual. I started and my period has actually lasted 4 days and still going somewhat. So my question is I've read women with shorter periods have a harder chance of staying pregnant meaning we would miscarry more often than if our periods lasted longer. anyone with insight on this?