BFP on cheap test

I got some cheap tests, they were reduced to 50p because of the date. I've got a faint line and I showed someone (a male) and he doesn't think it's reliable because it's cheap. I didn't want to spend out on tests to just throw them away. I'm going to buy a more expensive test to make sure it's correct but which should I buy? (I'm in the UK) I only had sex 16 days ago (only time I've had unprotected sex in months) should I do the new test today or in the morning?anks

Thanks