UK border didn't stamp my passport. HELP!

[silverfox]

I have an argentinian passport and came to the UK from Barcelona 2 months ago, on a tourist visa (6 months for Argentina) to visit my british boyfriend and I just realised my passport hasn't been stamped on arrival. I have an exit Barcelona stamp in my passport and a stamped boarding pass from Ryanair.
I'm afraid I'm going to have problems when leaving the UK, and also problems re entering Schengen territory if I don't have the UK stamp, as I am only allowed to stay in Schengen for 3 months.
What can I do? Shall I go back to the airport?
Any help will be much appreciated!

[CMOSUK]

I have an argentinian passport and came to the UK from Barcelona 2 months ago, on a tourist visa (6 months for Argentina) to visit my british boyfriend and I just realised my passport hasn't been stamped on arrival. I have an exit Barcelona stamp in my passport and a stamped boarding pass from Ryanair.
I'm afraid I'm going to have problems when leaving the UK, and also problems re entering Schengen territory if I don't have the UK stamp, as I am only allowed to stay in Schengen for 3 months.
What can I do? Shall I go back to the airport?
Any help will be much appreciated!

Is your passport a barcoded one? Or a biometric chip one?

As I'm pretty sure it is digitally logged when you leave and enter.

Also retain the boarding passes for when you entered and exit as evidence and any receipts if you buy from duty free area.