I would like to preface by saying that please do understand, that the job of the jungler is NOT making sure you don't suck.
If you gave first blood before level 2, and another subsequent kill, and then kept overextending so the jungler ganked you twice, all before level 5, it's not my job as a Rengar to gank you, especially not without my ult, and especially not against a Riven.
Junglers are there for map control and objective taking FIRST. Snowballing your lane is a secondary priority and even then there might be numerous other lanes that make a lot more sense to gank over yours.
If you're feeding. Stay safe, hug your towers, don't push the wave, and don't bite the hand that ganks for you.