Tier 5 GAB and re-entering the country in the extra 14 days

[Intronaut]

Hello.

I am from Chile and I have a Tier 5 Government Authorized Exchange multi entry work visa. My Certificate of Sponsorship ends the 31th of May but I have 14 days more to stay in the UK, so I can be here until the 14th of June. I booked my flight from London to Chile for the 11th of June. However, I would like to do a small trip in Europe after finishing my work here, but come back to UK to pick up my luggage and then return to my country.

My question is: there will be any problems in the UK Border if I try to enter just for two-three days? I ask this because my contract will be finished, so they could find weird that I try to enter the country without a contract, even if my visa is still valid.