BC messing with period?

Hi everyone. I was on Nexplanon for 3 years and had it taken out Feb. 24. My cycle is usually anywhere from 38-41 days (I know, long, right?) I’ve always been irregular but today is weird. My fiancée and I are TTC, we had sex on my ovulation day. Which (according to the app) was March 24th. Yesterday I started having light bleeding but only when I wiped. Today, it’s really heavy and need a tampon in. I usually start my period really heavy. I always have terrible cramps and nausea, but I have none. I have slight pain but hardly noticeable. I’m apparently not supposed to start my period for another 9-11 days. Could getting my BC out be messing with my period and my body trying to regulate? Or could I possibly be having implantation bleeding? It’s just strange that it’s heavy today, but no cramps, no nausea, and it’s really early. Any advice please??