As title, over the last few weeks I've noticed a smell of fuel, usually just after ive started it. It's not every time and it's not just when starting from cold, in fact i think it's more when engine is warm.
I've also noticed I'm using a lot more petrol and sometimes its hesitant, usually when revs are low in 2nd gear.

Ive not seen any evidence of a leak, nothing on the floor (would petrol evaporate away though?)
A diagnostic back in march revealed it needed a new lambda sensor, and after getting that replaced it passed the emissions test for mot.

So, I don't know if it's likely to be a fuel leak or a running problem?
Are there any checks I could do myself before taking it to a garage?

Thanks
Ellie x