The Foreign Office is advising against all but essential travel to Mexico. Three tour firms have stopped flights.
Nicholas and his wife on their Cancun honeymoon
Following the confirmation of two cases in Scotland, the health secretary said there would undoubtedly be more.
Nicholas Williams from Harrow in Middlesex contacted the BBC News website about his concerns that he and his wife may have picked up the virus while on their honeymoon.
Today I feel a bit worse than I did yesterday. Yesterday my wife and I drove ourselves to Northwick Park Hospital for the tests to see whether we have swine flu.
We were given facemasks to put on as we passed through the ward to get to a sealed room.
And then we had the tests.
One swab was taken from the back of our throats and another one from at the back of our nostrils. We then had to gargle water and spit it out in to a pot.
After this we had to sniff sterilised water through each nostril and then blow it back out again.
My wife has been prescribed Tamiflu as precaution.
We are waiting for the results. The doctor said she would call by the end of the day.
We came back from our honeymoon in Cancun, Mexico on Monday 20th April. By the Wednesday I became ill with a cold/flu and stayed in bed for 3 days.
I have a low immune system anyway but these were the worst flu symptoms I have ever had.
My condition has since improved but now my wife has become ill.
Our family came to visit us over the weekend to look at our honeymoon snaps and they were concerned about our health after the media reports of swine flu in Mexico.
We contacted NHS direct on Sunday and they told us to stay at home and to contact our GP.
My GP advised us to stay at home and not come in to the surgery.
The Health Protection Agency called us to confirm the details of where we had been and what we had been doing while abroad.
I am feeling better now but my wife is still in the early stages of her flu.
The Health Protection Agency say they want to test her for swine flu but at the moment local doctors do not have the swab kits.
The only way we can get tested is if we get ourselves admitted in to a specialist unit at Northwick Park Hospital.
Tamiflu has also been prescribed for my wife but no pharmacy in Harrow has it in stock at the moment.
We are quite concerned but not concerned for our lives. The media says Britain is prepared, but are they really?
We can not be tested as the GP/doctors do not have the equipment and we do not have any tamiflu in the area.
So we are just stuck at home until they have a meeting tomorrow but sadly this does not help us now, nor our family.
We don't know what to do apart from sit here watching the news.