How heavy can implantation bleeding get?

I know for sure that my ovulation took place on the 1st of January (7 days ago) and I start bleeding today in the morning. Its nowhere near as heavy as my period, but it's more then just spotting.

Tmi. Usually on the first day of my period, I hsve to change my tampon every 30ish minutes during the day. Which makes me use almost an entire box of tampons in the first day. But today I only had to change the tampon twice, so that makes 3 tampons instead of 60.

Also, none of the tampons were completely full. When usually every single tampon is do full that I have to wear a pad as well, to catch any blood that comes out before I can reach a toilet.

There aren't any clumps or bits coming out today, Just blood. And I only have very mild lower backache, whereas I usually have heavy cramps and sometimes have to take pain relief.

We weren't ttc but I'd still be happy to be pregnant.