Could be that your AF last was implantation bleeding, I've heard of women having heavy bleeding not just spotting during implantation. Could also simply be early pregnancy bleeding, many women have af like bleeding during pregnancy and carry on to have a healthy baby.
Personally, I couldn't see the lines on the frers you took last month, except maybe on 1 or 2, but those were super faint and looked more like evaps or indents. I've noticed a lot of issues with frers lately.. I've seen a lot of evaps that really looked convincing.
This is just my personnal opinion and I am by no means a doctor, so definitely call your doctor and book an appt asap