Depo causing long periods?

Hi all! I was wondering if anyone has had a similar experience to me.

I am almost 3 months postpartum and I started the depo shot about a month ago. Since I started it, I have had two periods - and one has been very long. This period has lasted 12 days so far, and my periods are normally 3-4 days. Is this just my body adjusting? If this is going to be a regular thing, I’m definitely not interested in being on the depo anymore. I was on it in high school for a few years and it made my periods stop, it never caused extremely long ones.

Just wanting insight or possibly advice!

TIA x ❤️