Don't know what you might have on your overhead panel Tee Emm, but a drop of oil pressure into the no, no region, but has not dropped low enough to bring on the lights, is certainly of concern.
The 737 that drained the wing tanks till the fuel low came on, but landed with a substantial load in the centre may have benefited from a scan of the overhead at some point during the approx four hour cruise.
Settled into the cruise when the pressure dropped into the yellow, with a corresponding temperature drop. Couldn't figure that one out, reduced power to idle to keep auxiliaries on line (twin aircraft) and landed ASAP. Following shut down ground crew reported a large amount of oil dumped on the tarmac, and inspection found the oil tank empty. Cause, a split in the tank to pump line. As long as the engine was operating it sucked air in through the split, which explained the loss in pressure and drop in temp. As soon as it was shut down the oil drained out via the split.
So yes, monitor those VITAL instruments.