Since today was a slow day at work I took the last two hours off to get to the garage (phoned ahead if they had time)
Well.... here's what happened.
First of all when I bought the car (second hand) they rotated the tires and forgot to update the onboard computer.
My garage didn't do that, they were just the mediator.
This means that I wasn't looking at the front wheels but at the back wheels. So front right wasn't the problem it was rear right.
Now I noticed that rear right was on the flat side about 1.6 bar instead of 2 but I didn't pay it no notion because I focused on the front.
They pulled out a big nail from my right rear tire, reset the computer and updated it.
So in short, my sensors were okay it really was a puncture
My garage Reset the computer and updated it with the right info
and offcourse fixed the puncture. They only charged me for the puncture (about 12 pounds) So including tip ( I allways leave a tip) I've paid 20 euros, about 15 pounds.
And my Megane is good again :-)
Ah.... peace of mind...