lifetime of irregular cycles and now suddenly 2 in a row?

Never have had regular periods. When I say never I mean literally never, even on some period inducing progesterone it didn't happen some months. I have been off of all fertility meds for exactly a year. Last month I had THE WORST period I've EVER experienced with pain, cramps, excessive bleeding, clots, the works. I'm talking, almost ER worthy pain. This month, I was only 3 days "late" from when the cycle should've started and it came all by itself. The period has been quite nice, actually... enough blood that I can tell it's a real cycle, only cramping the day before and 1st day of, bloating and fatigue. I'd say totally average. 

My question is why all of the sudden am I getting 2 in a row, and experiencing regularity on my own? My body has NEVER done this on its own, since my first period 10 years ago. Has anyone else experienced this? Do you think it will continue, or does this just happen sometimes to us irregular ladies? This is 100% out of norm for me. Not that I'm bitching, but, what gives!? 

I also want to add- my first period in forever last month (the awful one) started the day my sisters baby, my nephew was born. I have been around them super frequently and help take care of him often. We spend a TON of bonding time together. It started yesterday for this period, when I was taking care of him. Has anyone ever heard of this being a factor?