Is This Fish Pregnant?

Barbs don't get pregnant, strictly speaking, they get egg full. The ovaries fill with eggs, which can make the female look large; the eggs are then laid and fertilised or reabsorbed by the female.

However, there are other things that can make a fish look fat including over eating and dropsy - in the latter the scales will stick out as well.

The eggs are unlikely to have survived long enough to be siphoned up as the fish would have eaten them almost immediately. It is very difficult to get fry from egg layers without going to some trouble to prevent the fish in the tank eating them. To quote Seriously Fish, gold barbs are "egg scatterers with no parental care". The eggs would be very small so you wouldn't see any that did get into the gravel when you siphoned them up.

The odd one or two eggs can lodge in a safe hiding place - safe from being eaten and siphoned up.
The reason egg laying fish lay so many eggs is in the hope that one or two might make it through to adulthood. In the wild, the overwhelming majority will be eaten.