I've done a few searches so I have read a few bits of advice.
first time sufferers 
had ovex 24hrs ago however my dd1 and ds have had the sickness bug. will they have brought up the ovex? they were fine through the night so had at least 12hrs of settled stomach.
just had the last shower and change of the day and dd1 certainly had a active little fecker making his way out
I know it can take up to 48hrs to work but will it work at all with the sick problem?
dd2 has been at school and ok... When I bathed her I couldn't see any movement but perhaps eggs? boak
ds didn't appear to have any at all
I've gone overboard on washing, cleaning and hoovering etc so taking prevention steps.
I also appear to have the problem, last night was hell and I don't feel that they have left iykwim? 
do I re dose the sick ones tomorrow? or wait? We're all very freaked out as it is!