1st period so soon

Hi there so I’m breast feeding and only breast feeding (using a nipple shield due to flat nipples) and I got my period 4 weeks pp.

I only bled for about 4-5 days after labor and it was pretty light after the first two days. But this period has been so so much worse. I’ve never experienced it before.

My question is has anybody had their period so soon after giving birth and while exclusively breastfeeding? I was told it could take months.