We do not exact
The timing and exact causes of the ice ages are not well known enough to say if we should have already entered another one.
Any statement otherwise are pure speculation.
Feedbacks, if positive, would have to show up in the temperature record, beyond the the forcing warming.
Land and sea cover loosing their ice would affect albedo, but such loss would have to be somehow different than the rate of loss already happening.
Consider that absent Humans, the same cycles happened, ice loss and albedo reductions occurred, until they did not, and the cycle reversed.
Basic Physics says that if the energy imbalance were present, the temperature would be forced to increase.
Within the record, we have a recorded warming period, and a latency period. The post warming period should
contain the warming from any new forcing, any natural or other man caused warming, AND the portion of the feedbacks within that latency period.
Hadcrut4 shows that Globally we had .258C of pre 1950 warming, and warming of .703 C between 1950 and 2015, in the decade smoothed record.
From 1950 to 2015, the AGGI also records that most of the greenhouse gasses increased to cause forcing warming of .579C.
The difference of .124C is all that could possibly be considered positive feedback, but that would be before any other factors were considered.
From 1950 we still had several years of TSI increases, and we also had an increase in insolation from ~1985 to 2015, and the accuracy of the record itself.
Global Dimming and Brightening
So again there is noting in the instrument record, that could be pointed to without question as positive feedback, yet some should be there.