Nexplanon implant and irregular periods?

I had my second baby August 31st 2019 and 6 weeks later I opted to get the Nexplanon implant. Ever since, I’ve been having the weirdest periods to no periods at all. Every ‘period’ would be lots of cramping but the color of the blood is always brown like it’s old blood. I only spot for a couple of days and then I won’t get another ‘period’ for a month and a half to two months later. TMI but if anyone had any similar experiences I’d love to know I’m not the only one 😂