l have recently poured 23m2 of concrete at the back of my house to pave on, because of the depth in which i excuvated the site, i thought i was unable to pin it to the house foundation, so i did not, but then i thought i could of under pinned it but the concrete just kept crumberling and as concrete turned up i left it not pinned, what could be the consequencers and how likley are they to happen. l compacted 50mm of rock [cement mixed in] under the slab, used f62 mesh and poured a 60mm depth of 25mpa concrete, i will be paving 20mm bluestone pavers on a 20mm of mud. ive created a 150mm step down from the house,so if the slab does settle will my step possiibly become greater?
thanks

It sounds like you have done everything ok, even if your slab dropped 25mm you would still be ok for step height.