Can your GP get you out of a holiday if your pregnant?? help?

I have just found im pregnant im in my first T1 but as excitied as i am cant tell anyone yet but i have book a holiday for Aug with my pals to Ibiza, with it the madest of hotels also , party central. There is no way i can go their 5 months pregnant and doubt my hotel would let me stay there 5 months showing and neither do i want to ruin my pals holiday with my soberness! I have paid my hol in full part being on a credit card, can be GP write me a letter to cancel my place which wont leave my friends in financial bother as thats the last thing i want i rather the travel agents kept the money if that was the case. Anyone or Doctors out their know?? As i do know if a medical condition then theirs a poss but think has to be serious rather than being pregnant . lol