Menstration After Birth

It varies - would be the short answer.
What I had read is that strictly breastfeeding, including at night is effective birth control for the first 6 months only- which I would translate into having no period.
What I have experienced is that for my first, I did not have a period for 7 months, although she slept through the night at 3 months. For my second, I have still not had a period (13 months), but he has only been sleeping through the night for about 4 weeks! (Finally!!!)

My other thought is that what I was told after having my little people is that it is common to bleed for 6 or so weeks after giving birth, just from giving birth. You are close enough to that time, that I would guess in that direction. Although that said... back to my first line - it varies! Probably not too helpful, but thought I would throw my thoughts in.

I was still having post-delivery bleeding at 7 weeks but after that stopped, I too was breastfeeding and did not have another period well into the first year. If you've noticed a link between exercising and spotting, maybe your body is still recuperating? I'd just be sure to take it slow, listen to your body, maybe stick to very light/gentle exercise like swimming/walking. Please be sure to talk to your doctor if you are concerned :-)

I also strictly breastfed. My period started regular again when my baby was 10 weeks old. No break for me except for the 9 months of being pregnant!