Fertile cm

Has any gotten fertile cm like 3 days after their period.... this is the second time recently that I’ve actually gotten it. We have been ttc’ing for 3+ and this is only the second time I’ve gotten it. But wondering why it’s only 3 days after my period. My last cycle was 160days 😞 but two weeks before my period was when I first got fertile cm and now again I’m in shock I even seen. My periods have always been off but never this bad it’s only after our ectopic pregnancy it went completely south. But I’m trying to stay hopeful 🤞🏼