Short Cycle after pregnancy loss?

I just logged both of the bleeds i’ve had since my miscarriage bleeding stopped in december (previously i just logged the longest one) & now my app is saying this. Which makes sense as i’m definitely not ovulating like the app predicted before when i just logged the longest period.

For 2 days i’ve had light brown spotting, no fresh blood , only light brown mucous/ old blood? If this is correct then we BD on ovulation day & could it be implantation bleeding now? So many questions. Apparently some people have short cycles after their miscarriage. I didn’t realise this was a thing. I’ve never had regular cycles so this is all new to me.