Breastfeeding/ttc question

So I've been breastfeeding my little one for a year now when I started my period... I'm just confused with my oldest when I got my period back it was the WORST, very heavy flow. And this time around I've just been spotting.. not enough for a tampon. I do change pads multiple times a day but If i didnt i dont think i would have even filled it up all day and night. That's how light it was. I did this for about 3 or 4 days. No cramping and if I did it was very light. Blood was bright red/light pink no brown. Ugh. Husband and I haven't been using protection so possibly implantation beeding? I've also been dealing with backache and leg cramps...similar to right before I found I was pregnant with my second.

Anyone else gone through this before?! We're trying for our 3rd 🤦‍♀️🤷‍♀️