Vfl on 8dpo?

I am now 12dpo and my lines have gotten darker and darker, but my question is: is it normal to get a vvfl at 8dpo on a frer or is it more likely that I ovulated earlier than I think?

I got a positive OPK on 20 Dec so I am assuming I ovulated on 21 Dec but I don’t temp.

Thanks 🥰