996 Turbo petrol smell

[Brinyan]

I usually run my 996 with plenty of fuel in it. However, whilst using it over the weekend I let it run quite low , to the extent that the fuel light came on & dashboard warning to beware of limited fuel. Prior to this I was aware of an odour of petrol. Any ideas why this may be so?
I filled up & think the odour has gone. Can’t be totally sure, as was a short distance home & parked up, not had a chance to drive it since. Thanks