Positive OPK on CD 8?

Hi there! So. My cycles are pretty irregular. I got my cycles back in June after having my son December 2015. I have had 4 cycles and they have been 55 days, 81 days, 30 days, 35 days. We just recently started TTC. I use the lady comp to chart my temp, but since I'm still nursing, I don't always feel it's 100% accurate. 
Anyways. AF ended Monday. I got a negative OPK yesterday and a positive today. I even took two different kinds because I thought it seemed super unusual to get a positive OPK so soon. No temp shift yet. Is it possible to ovulate so soon after AF? 
Top is answers OPK and bottom is first response fertity OPK. 
TIA ladies!